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Precipitation and Crystallization of Metal Salts


The research report intends to make an in-depth analysis of the resulting complex structures formed as calcium silicate crystalline and coagulate in distinct structures. The average thickness of the developed structures observed under the IR camera gives a clear view of the structures.  Consideration of precipitation as the primary process of particle grouping is suitable for drawing the overall conclusion since the reaction, and crystal formation occurs at room temperature and the affinity of different molecular ions control the entire process. The adoption of current technology that uses the MATLAB software gave critical statistical information about the reaction that took place between calcium and silicate solutions. Solidification and precipitation of particles into complex structures provided solid confirmation of the trends of structure formation at the influence of calcium ions in the solution. The tracker images revealed the stages involved in precipitation of calcium silicate from the solution.  Successful accomplishment of the analysis enables the students to advance the precipitation analysis for another metal salt structural analysis.


1.0              Introduction

The process of precipitation dominates crystal extraction in solutions. The complex metal structure formation often relies on initiators that accelerate the process of solidification of compounds. The study of calcium silicate precipitation and crystallization process provides an elaborate analogy applicable in the chemical industry regarding crystal formation. The study involves precipitation analysis from the solution and atmospheric air interface. The reaction between calcium ions and silicate reagents like amorphous silica generates a stable molecular structure that undergoes crystallization to develop complex structures of the metal salt. The research objective is to assess metal silicate structures that result from precipitation and the effect of inhibitors on crystal structure development (Lantelme & Groult, 2013). The evaluation of precipitation inhibitor on the precipitation process will improve the environmental conditions adopted during the experimental process. The mechanism utilized during polymerization involves analysis of metal salt solubility. The precipitate formation is a continuous process that undergoes a multistage transformation of molecules in the presence of heat.

The process begins with nucleation that increases the concentration of ions in the solution until ion cluster form on the surface of the solution. The resulting clusters build up to a point they are large enough to remain stable on the solution surface. Precipitation or scale growth of complex structures of metal salt depends on either ion by ion or nucleus by nucleus propagation. The two methods adopted produce a distinctive precipitated form of salts.  The ion-based method generates smooth scales as ion sizes reduce as deposition rate fall (Davis & Edwards, 2014). The resultant crystal is small in sizes, more compact and with smooth surfaces while, the crystals formed through nuclei propagation develop into larger clusters that build up into rougher, imperfect crystals entrapped at the faster-developing rate. Intensive analysis of chemical garden principle reveals adequate information relating to the formation of the plate-like structures during calcium silicate precipitation. During the reaction process between water molecules and metal pellets, the formed semi-permeable membrane shields crystals from the effect of water, thus initiating the process of reverse osmosis that allows water to move from silicate solution to calcium pellets and facilitate cyst development. The concept of the structural performance of every grown metal salt crystal is essential in the study of their performance and chemical properties governing possible applications of the product.

2.0 Mechanisms of Metal Structure Formation

Silica exists in a solution as sialic acid presented Si(OH)4, as the concentration of silica increases, crystallization process begins to lower the molecular weight and the crystal continues to develop into longer chains of colloidal polymer that form silica gel (Evdokimov, 2012).  At a concentration beyond 100ppm calcium silicate precipitation rate advances with an increase in temperature and variation in both pH and total dissolved solid  (TDS).  Deprotonation rate increases with advancement in pH, since silica is a weak acid the resulting polymers poses similar property, through the acquisition of negative charges at high pH values. For instance, the pH of 8.5 makes silica gain 10 percent silica anionic molecules leading to solubility increase by 10% as the silica ions repel one another in the solution determining collision hence, facilitates polymerization process of the particles.

Si(OH) 4 + OH = H3SiO -1 + H2O

The addition of polyvalent cations like calcium ion acts as coagulants with repulsive neutralization charges, reducing the influence of pH on the system. Calcium ions present in the solution become hydrated as the pH of the solution advances. At neutral pH, dissolved calcium exists in the form of calcium hydroxide precipitate in amorphous metal particles with low solubility levels and crystallizes at a relatively lower pace. The absorbed larger quantities of silicic acid in the solution generate different layers of precipitates that support the formation of crystals. The interaction of resultant polymerized silica layer with calcium lead to the occurrence of silica fall-off that develops layers or membranes even under unsaturated condition. Dissolved calcium may react with monomeric silica to precipitate either calcium silicate with similar chemical composition, but distinct crystal structure (Remington & Behringer, 2006).   The process is quite slow and takes considerable time to generate a sizeable quantity of precipitate.

Precipitate formation mechanism and structure comply with the 2D growth of hexameric ring units without a specific core link. The initial stage of calcium gel formation involves neutralization of calcium solutions with reagent of silicate. The study of small X-ray images of the cluster formed depends on the OH: Ca ratio for short chain linked a group of low fractal dimension and sizes. As the tetrahedral of calcium reduces, the cluster increases in both dimensions and size then become relatively compact. The long range of crystalline order develops due to the slow cooling process of solution during precipitation (Vasil, & Zaikov, 2009).

2.1   Silicate Precipitate Characterization

Formation of silicate precipitate occurs during polymerization.  Formation of amorphous structured silicate salt occurs during polymerization phase. The composition of silica precipitate consists of metal complex salts and some silicate molecules. Analysis of trivalent metal silicates and other traces of calcium and magnesium silicate salt precipitation provide detailed information regarding the growth and development of metal salt structure (Masuda, Higashitani & Yoshida, 2007).

2.2     Structure and Bonding in Salt Precipitation

The analysis of structure and bonding pattern in metal salts often involves a cation transfer effect on the reagent preferably alkaline of silicate, while cation coordination depends on the linkages developed by the anion part from the reagent. The reaction generates a stable crystal structure that solidifies under temperature variation to form precipitates that settle in indefinite shapes referred to as salt structures. The formation of divalent salt bonds produces a relatively stable molecular structure that affects precipitation process (Evdokimov, 2012). The bond type developed to alter the crystal packing pattern regenerates during crystal growth and structure formation. 

Factors that Control Precipitation Process

The dominant parameters that regulate crystallization include the concentration of cations like calcium, anion concentration like silicate, the pH of the metal salt solution and the temperature of the solution. The level of solubility of cations and anions affects the solution concentration as pH regulates the performance of alternative compounds. Hence, affects the precipitation process, for instance, silicate dissolved in acidic solution and precipitate under immediate environment will give different results from the pH of solutions used in each case (Walsh & Vidal, 2009).  The incorporation of polymeric additives may act as a polymer bridging or charge neutralizer to produce metal coagulants.

2.3 Charge Neutralization

Precipitation and formation of crystals depend on the pH value of the solution and affects the performance of a metal ion transfer process within the solution. Free, hydrated ion experience limited adsorption rate in a negatively charged solution compared to hydrolyzed cations like Ca (OH) 2+.  The process of charge neutralization takes place at relatively low metal concentration. A solution pH of 6.5 of calcium silicate is satisfactory in lowering electrolytic mobility in the solution to zero even at a low level while at neutral pH; a small amount of soluble calcium will neutralize the solution and facilitate precipitation. Hydroxide particles constituted significant charge neutralizing species. The dominant mechanism adopted in precipitation of metal salt is the surface precipitation that is appropriate for bulk crystallization of particles (Lantelme & Groult, 2013). The positively charged metal hydroxide in a negatively charged solution of the silicate facilitates charge transfer and in the event results into colloid development after some time.  Under correct dosage, complete neutralization increases the rate of precipitation process. Once the coagulation dose corresponds to electrophoresis mobility, the precipitation of calcium silicate salt will be efficient and faster.

At higher pH of about 8 – 9, the quantity of calcium metal required to neutralize the reagent and generate meaningful precipitate must be high to maintain the electro-kinetic properties of the solution (Remington & Behringer, 2006).


The presence of stoichiometric relationship exists where charge neutralization is the dominant precipitation mechanism. The dose range regulates the pace of coagulation of the colloids.

2.4 Sweep Flocculation

The process of rapid and extensive hydroxide precipitation allows for optimal extraction of salt particles. The possible impurities in the solution enmeshed in the hydroxide precipitate and the suspension.  The process of sweep flocculation increases crystals quantity through variation in the neutralization process due to increased solid concentration in the solution. The precipitated molecules often exist in more open structures to an extent that a small mass gives larger concentration, volume with a higher probability of attracting other particles. Binding of particles by precipitated hydroxide may present stable aggregates. An increment in coagulant dose in the solution gives larger volumes of precipitates greater than optimal dose; thus, facilitate minimal improvement in the whole process (Tian, et al., 2010).  Particles of calcium hydroxide take more time in a solution of pH8 to precipitate increase in the molar concentration of calcium silicate solution accelerate the process of precipitation. The disparity existing in precipitation trends at a different molar concentration of calcium confirms the influence of charge neutralization and sweep flocculation. In case the sweep flocculation precipitation rate is rapid, massive structures develop that start with the formation of bulk hydroxide precipitates in small colloids. The crystallization process begins around the impurity of seeding particles present in the solution.  The adoption of Smoluchowski theory attributes flocculation rate to be proportional to the effective particle volume. The existence of small portions of molecules in the solution accelerates the precipitation rate in the sweep flocculation process while particle neutralization immediate minimal impact on the advancement of the colloid radius.

2.5 Effect of Anions

Precipitation highly relies on the calcium metal ions present in the solution. The effects of anion define the replacement trends of hydroxyl ions and their effect on kinetic of precipitation. The existence of destabilizing ion affects the pH of the solution that in the event dictates the process of particle coating within precipitate. The solubility of the anion in the solution affects precipitation rates of metal salts in the mixture. The presence of silicate ions in the solution advances the rate of precipitation rate of metal salts. The presence of anion in the solution helps in regulating the pH levels, while, low pH values depress the solution and restrain the precipitation rate of metal salts in the mixture. Silicate solution has a significant effect on the metal precipitation of either accelerating or reducing the rate of precipitation depending on the concentration and pH level of the solution (Lantelme & Groult, 2013).

2.6 Temperature

The solubility of metal salts is high as the temperature increases. The establishment of solid state equilibrium depends on the temperature differences of the solution. The rate of solubility of metal salts depends on the temperature of the mixture. The rate of silica solubility increases with increase in temperature. Therefore, precipitation process will commence as cooling process begin noting that at elevated temperatures the solubility of salts is high, resulting in increased saturation of metal salt content in the solution. The calcium ion tolerance of polymer reduces with increase in temperature. The two factors that dictate precipitate structures of metallic salts is the advancement in silica saturation at high temperatures caused by an increase in solubility and silica polymerization that vary in a direct proportionality with temperature. Variation in temperature plays a significant role in precipitate characterization and performance within the complex metal salt analysis. The rapid reduction in temperature during crystallization produces crystals without clear structures as the coagulation time is limited. Therefore, the development of great structural shapes of the precipitates requires controlled cooling that gives metal salt particles time to glue and create complex structured particles (Pignataro, 2010).

2.7  Effect of pH

Solution pH has a critical impact on solubility and precipitation trends. The advancement in pH from 6.5 to 8.3 and above make the solution have excess hydroxyl ions hence reduces the solubility of silica. Since the solution is more alkaline formation of metal silicates will increase, therefore, generation of structures of metal complex salts through the precipitation process requires the solution pH to be in a slightly alkaline state of optimum ion transfer and ample crystallization. The increment in alkalinity further affects the rate of solubility of silicate, thus, influence the level of available anion that reacts with cations from calcium cilicatesalts to produce larger components of precipitates (Walsh & Vidal, 2009).  The pH plays a central role in coordinating the balance between the compounds dissolving rates while under optimal pH of the solution, the structures form faster and develops the considerable masses that are observable under a microscope or naked eye.

2.8 Inhibitor Concentration

The concentration of the reagent used represents the dose blend of the copolymers that affect the performance of silica in the reagent. Therefore, the use of optimal concentration of the chemical inhibitor of about 70mg/L of copolymer blend dose will provide a suitable composition of the reagent that once reacted with metal salt produces a desirable precipitate that develops into precise structures (Tian, et al., 2010).

2.9              Inhibitor Composition

The inclusion of relevant components of chemical inhibitors is necessary since the reactions and precipitation process involved during the colloid formation produces positive test results that support the performance of metal salt during structural development. Therefore, in every stage distinct blend of appropriate additives is critical for instance the use of PBTC or BA additives are suitable for use as calcium carbonate inhibitor in the solution. The research presents the application of polymerized polyacrylates as the best and adaptable inhibitors that tolerate a wide variety of salts.  Regulating the reagent composition to less than 20 percent silica inhibitor ensures the proper selection of the mixture in the presence of calcium metal salt solution (Walsh & Vidal, 2009). Polymer doses in the range of 10 to 50 mg/L are appropriate for regulating the performance of polymer blends. Proper composition of inhibitors in the chemical reaction will positively result in the formation of stable structures of metal salt compounds due to complete reaction of the molecules.

2.10          Ions Effect

The increase in metallic ions increases the hardness, as well as, the polymerization of silica and has minimal influence on the metastability of the solution. During precipitation, increased ion level in the mixture accelerates silica polymerization, though present minimal alteration in the structure of polymerized precipitate (Vasil, & Zaikov, 2009). Silica polymerization inhabitation increases with the advancement in metal ion concentration, hence, bear significant influence on the precipitation rates of the salt samples used. In the case of a supersaturated solution of silica, the precipitation of metal complex salts included production of specific precipitate structures.

2.11          Effect of Total Dissolved Solids

The inhibition of metal salt precipitate-deposit from the solution depends on the existence of total dissolved solids that relate to the content of dissolved salts in the mixture. The increased ionic strength controlled by the level of total suspended particles elevates the polymerization of silicate thus resulting in improved precipitation trends of metal salt solutions. Total hardness in a mixture depends on the amount of calcium metal salt present in the solution that affects the charge density and precipitation rate of salts (Lantelme & Groult, 2013).

2.12          Effect of Thermal Stress on Precipitation

Thermal degradation is the tress resulting from the variation of temperatures in the process of precipitation contrary to the recommended temperature trends that allow for precipitation and crystallization of metal salts into definite structural shapes. The elevated pressure and temperature of the mixture affect crystal growth of calcium precipitates into the particular structure (Vasil, & Zaikov, 2009).  The condition of thermal stress in precipitation of complex salts inhibited crystal formation even under higher saturation in the solution. As a thermal effect advances the occurrence of definite structures during polymerization seizes, while, the colloids develop into fine crystals without crystals. Cooling of the solution at a faster rate will accelerate the process of crystallization, producing crystal particles without clear cleavage. The stress-free environment is the best condition for the production of salt precipitates with definite crystals and structures.

2.13          Surface Tension

Surface tension involves the analysis of silicate and chloride performance by bubble pressure at the solution surface. Even though, the surface pressure often fluctuates by atmospheric pressure variation trends are more dependent on the reaction and performance of metal solution during crystal growth. The Surface tension defines the ratio of exposed reactive layers of the substance to the available reagent. It affects the rate of crystalline structure development, as well as, the nature and size of the metal structure resulting. Increased surface tension between the solution and reagent deters the reaction process, hence, reduces the crystal development rates.  The slower the rate of crystallization the larger the resulting structures. Therefore, an increase in surface tension to optimal value is an essential consideration during the precipitation process of metal salts (Masuda, Higashitani & Yoshida, 2007).

2.14          Solvent-Mediated Transformation

The mechanism adopted insolvent mediated transformational polymorphic phase crystallization involves dissolution of metastable particles to stable forms, implying that the process of decay is two-fold.  Super saturation of the solution occurs under the influence of stable shape and once the nuclei form in the saturated solution crystallization commences (Lantelme & Groult, 2013). The process advances and forms a stable-observable structure in the solution. As the solution becomes weak, metastable forms dissolve and provide a saturated solution that facilitates charge transfer. Such processes of crystallization rely on the solubility difference between anhydrate and hydrate; hence, the face transformation increases with advancement in solubility difference that may depend on the temperature and solvent volume in the system. The addition of additives induces a distinct effect on phase transformation due to either thermodynamic or kinetic effect.

3.0              Experimental Set Up and Procedure

Investigation of the structures resulting from precipitation process of calcium metal silicate salts that produces complex structures. Set the apparatus at room temperature and add the reagent to the test flasks. Use a syringe and hypodermic needle to add the metal solution to the flask (Gai, & Boyes, 2013). Monitors the effect of flow rate on crystallization rate as the solution react with reagent in the process of addition.   The concentration of the metal salt solution is critical since it is the ultimate determinant of crystallization potential for cation and anion extraction from the solution taking place flak.  Let the sample precipitate undisturbed and make an observation by IR camera to extract images of the resultant structure at an interval of thirty seconds and precisely mark them for analysis. Use prismatic elemental mapping tool to determine crystal morphology of the collected precipitates. Repeat the process for different metal salts and obtains data for structures formed.

4.0              Observations

4.1              Relatively Growth Structures with Varying Solution Concentration

Crystal growth and structural adjustments depend on the level of concentration. High concentration accelerates the rate of crystal structure development. Large structures form within a limited time interval as the solution concentration increases (Haudin, Cartwright, Brau & De Wit, 2014).

4.2              Energy Variation While the Flower Grows

The structural growth kinetic energy reduces as the flower structured crystals increases in size over time. The electron probe shows an indication of reduces particle deposition rate at an advanced stage when the energy is low. The energy variation in direct proportionality to skeletal growth rate, for instance, the observation of energy performance as flower structure grows with thermal IR camera indicated that energy value in the solution drops from 0.6mJ to 0.08mJ as flower increases in size and mass (Davis & Edwards, 2014).

 Bands Structure

The resultant bands structure revealed needlelike prismless enamel crystals exhibiting no boundary layer with crystal growth extending beneath the solution surface. The resulting observed band structure development by the electron microscope revealed an abrupt variation in the packing of the minute crystals that occurred randomly at shallow tone attributed to the continued reduction in ameloblast activity in the solution (Lantelme & Groult, 2013).


Fig band structure (Gai, & Boyes, 2013)

4.3              Relationship of Bands Structures with Flow Rates

The variation in flow rate affects the deposition and structural formation speed. The magnitude of flow rates present significant variation in the resultant structure, for instance, an increase in flow rate of the solution into the reagent increases the pace of particle deposition into bands resulting from the advancement of band size. Vertical deposition and elongation of the structure did not occur at constant flow rate confirming the impact of flow rate variation on structural development of metal salt structures (Haudin, Cartwright, Brau & De Wit, 2014).

4.4              Crystal Structures of other Metal Salt Solution Vs.  Calcium Chloride at the Same Density

The type metal salt solution dictate the resultant crystal structure since every metal have distinct crystal lattice and shape that is quite critical of structure development face (Davis & Edwards, 2014). For instance, calcium chloride exhibit increased precipitation at low temperatures where the density and temperature of solutions are the same the calcium chloride solution will form crystal structure faster compared to other metal salt solutions.

5.0              Result of Calcium Silicate Salt Precipitate Structure

The images of calcium silicate precipitate obtained presented the significant result of metal silicate salt structure generated through precipitation of solution (Tian, et al., 2010).  The increased concentration of calcium atoms presented polymer consisting of multiple calcium and silicate particles developing phosphonates of higher affinity for metals compared to other hydroxides that produced indistinct precipitate structures.

Complex metal salt precipitates are acidic hydrates that exist in the link of metal ions create a stable link in a crystal structure resulting from precipitation processes. Precipitation of any kind often begin with spiral growth from the center and as the process of precipitation advances, the growth spreads to towards the edges of the existing colloid. The occurrence of disjoint precipitation takes place where the ongoing precipitation process halts and begins in a different location. During disjoint precipitation, the shape of precipitate seems to develop from several points of the initial spiral growth. Mostly the formation of lighter precipitate structures is faster while dense, dark precipitate form gradually and develops outward slowly resulting in radial precipitates structures. Other forms of precipitation take place slowly and steadily growing fingering patterns of bands separated by small gaps. The inlet of calcium silicate present progressive process of precipitation that extends to the transition layer hence creates new bands that separate the precipitation. The complexity of chemical garden structures is possible through injection of the reactive metal salt solution in a restricted geometry with regulated flow rate and reagent concentration to sustain the study of the phase diagram in a replicable experimental environment.  The precipitation process that produces metal salt structures is a flow driven reaction. The adoption of modeling and numerical simulation simplifies the injection-based precipitation of complex metal structures in the reagent (Kawata & Masuhara, 2006; Haudin, Cartwright, Brau & De Wit, 2014). The concept of structure analysis sustains precipitation and deposition of particles in hydrodynamic systems.

5.1              Radial Precipitation Structure

The development of precipitate involves periodic pattern, and the view of the structure from the side of the calcium solution gives corresponding images to the solution surface.  In the case of metal salts, the precipitate growth advances with visible particles of salt from the surface to the lower side and extend into the solution. Increased accumulation of particles drastically reduces the visibility of precipitates that tend to have more outward growth contrary to the infrequent occurrence (Tian, et al., 2010). Aerial view of the precipitate reflects the lighter appearance of the colloids and as the process of precipitation progresses thickening advances and the appearance of precipitate become opaque due to the continued addition of new particles on the earlier developed particles from, the lower side.

5.2              Boarder Structure Formation

Boarders are the distinct white lines that mark the periphery of every deposited precipitate. In the case of calcium silicate structure, the boarders are of white color at the edges, copper metal salts will show blue precipitates as ferrous posses dark green precipitates at their edges. The resulting boarder structure indicates the possible complex metal salt involved in the precipitation process. Injection of the metal solution with higher molarities will increase the pace of precipitation in the silicate solution but the solution with molarities level less than 0.5 will take more time to produce an observable precipitate in the solution (Pignataro, 2010). To develop observable images, the electron microscope with higher resolution power gives reasonable pictures that provide sufficient data to support the analysis of precipitation process and resultant structures.

5.3              Propping Gelatinous Structure

The use of higher concentration of silicate solution produces an almost transparent precipitate that forms gelatinous structures with thin layers. The structures can rejoin once broken while in the solution. Such structures become brittle and delicate when exposed to the atmospheric air.  The rate of crystallization and formation of the precipitate structures is faster and reaches the surface within 20min from the time of initiation (Vasil, & Zaikov, 2009). The structural growth has been often from the surface into the solution. The color of the precipitated structure shifted from transparent to dark as the structure approaches the boundary layer associated with a low concentration of salt.

5.4              Coral Precipitates Structure

The precipitate of metal salts may start with the development of dome-like column structure referred to as Solomonic columns. The structural membrane does not support continuous rapture. The structure shows spikes that develop from the cracks emerging from the dome. The structure is typical in calcium silicate salt precipitates. Precipitation process is faster, and the structure develops over a period of about four hours to a reasonable height. Structural growth is from the solution base towards the surface. The broad base of the structure allows for safe removal of the coral structure of the solution without crumbling while the tubes are delicate and may crumble with ease once out of water (Gai, & Boyes, 2013).

5.5              Tower Structure

The structural development is vertical, and the internal membranes developing have no relationship with the flower structure. The process of development involves generation of radial symmetric fingerlike patterns in the later stage based on the size difference recorded in the structure (Allcock, 2008).  The spikes are relatively compact to an extent that they depict a single fluid source.

5.6              Tubular Structure

During precipitation, the crystallization of metal salts occurs taking the shape of a tube. The formation of cement in a calcium silicate garden relies on the tube deposits. Tubes often have steady growth rate. The advancement in length compels the tube to crumple at the base, and the new tube develops from the base of the crumpled tube. For sustained growth and development, the chemical cell releases some solution from the newly formed tube to limit the fluid flow to the older tube. The process makes the older tube to grow thinner then disintegrate into two narrow tubes. The growth and development of new and older tubes from the precipitates happen at the same rate (Masuda, Higashitani & Yoshida, 2007). Deposition of precipitate in a tubular structure within a controlled environment depends on the tube diameter.

From the study of precipitate deposition rate, lowering the concentration increases the advection growth in the plume. The differences in density lead to the vertical growth of the tubes as the process accelerate precipitate transfer and deposition (Walsh & Vidal, 2009; Kaminker, Maselko & Pantaleone, 2014).  Osmotic differences exert pressure on the solution causing up word mobility, thus increases the parse of precipitation of metal salt colloids. The Linear increment in pressure during tube precipitates structural development result in a drastic pressure drop at the stage of rupture near the base and as the pressure increases in the system, new tube is developed from the site of the fracture. In the case of new tube development one end has to remain open for the normalization of surrounding fluid pressure inside and outside the developing tube, thus maintains the external environment at the equilibrium state through restrained oscillation and relaxation motions in the solution. As the length of tube advances, the pressure increases steadily. The increased pressure will cause more stress on the membrane. The pressure difference is greatest at the base and open end. Once the pressure difference at the tube base reaches a critical level, the tube crumples creating new tube at the rupture zone thus reduces the internal pressure and flow to the old tubes. The tubes seals and the growth terminate.

The short tubes inhibit faster growth and development than longer tubes. The presence of the viscous drug in the solution increases the pressure in the tubes. The growth of multiple tubes is common and follows the principles adopted during the growth and development of a single tube by applying the understanding of multiple tube performance. The tubes often rely on a single flow of solution from the source. Therefore, subsequent individual tube discharge is a function of time taken to direct the flow between the tubes. The existence of tubes of different radii presents progressive growth, but the narrower tube progresses for a limited length and terminates as the larger diameter tube continue to grow. The reduction in solution discharge causes shrinkage of the tubes due to reduced reaction process at the chemical front (Tian, et al., 2010). The analysis of tube structure during metal salt precipitation widens the possible application and adoption of chemical garden concept that supports the colloidal structural development taking place in the solution. The rate of tube structure development depends on the buoyancy of the external and internal solutions.

5.7              Jetting Tube Structure

The development of precipitate structure begins from the solution base boundary and developing tubes are hollow and delicate due to the composition of the thin wall. The structure undergoes complete destruction when extracted from the solution (Andrews, Scholes & Wiederrecht, 2010).

5.8              Solomonic Column Structure

Solomonic column develops the spiral surfaces structure. The columns undergo continuous rapture that makes the resultant strand climb and produces smooth structures, but not compared to the initially developed columns due to the existing tracks (Kawata & Masuhara, 2006).

5.9              Spiral Precipitation Structure

The principle of chemical gardens involves the growth of mineral aggregates in three-dimensional plant-like forms that share properties with self-assembled structures at the hydrothermal vents. Mostly, the growth and development of spiral structures depend on the buoyancy, osmosis, and reaction-diffusion process. The chemical garden generates new patterns of the spirals, flowers, and filaments. The injection of sodium or calcium silicate into the solution initiates a precipitation process at the viscous finger. In case, the metal complex salt is of higher concentration compared to sodium silicate then the growth of compact pink circular precipitated begin in a radial pattern.  The stabilization of circle rim extends towards the wavelength like hair as critical radius advances. Advancement is in the range of applicable reactants resulting in a thin growth of the structure with the compound turnaround from flower to filament occurs smoothly at a fixed larger concentration of sodium silicate. The presence of intermittent concentrations presented with worm features emerges from the middle lower section of the image. Observation of worm structure occurs through the micellar system under the formation of gel products at the interface of reactive solution (Evdokimov, 2012).

The terraces-like precipitates develop along the initial structure of the metal salt solution. Advancement in metal salt concentration increases the structural transition from hair to worm and then to filament structure. The transition from intermediate value presents compact structures that are not extremely delicate outside the solution. The spiral development after the subsequent breakup of precipitate walls will start after a long time as the precipitates with prominent color start growing from their semi-permeable walls. The variation in color tone within the precipitate structure indicates the existence of different solid phases in the reaction zone at the boundary of the two solutions. The concept of friction has a negligible effect on the structural outcome of the precipitation process due to the absence of a sick – slip situation during structural growth. Precipitates existing in spiral shaper are robust and exist under a wider range of concentration, and they exist in the reverse gardens process (Seidel, 2011).

5.10          Geometry of Spiral Structures

Spiral formation relies on the pure geometry. For instance, the radial injection of a metal salt solution with the reagent facilitates precipitate growth circles of small radii. A further injection of salt solution alters the radius of existing precipitate as the resultant bubbles of reagent pushes the existing layer leading to the formation of a branched precipitate around the growing bubble that rotates around the breaking point representing the spiral tip. The logarithmic construction of the helical structures of complex metal salt precipitates corresponds to the polar coordinate equation that quantitatively describes structures in the natural environments (Pignataro, 2010).  For instance, the growth and development mechanism observed in the seashells, snails or polyps preserves the shape and addition of materials occurring at the growing tail increase the length and mass of the precipitate while retaining the overall shape.

5.11          Spiral Stand and Flower Structure

The spiral crystal column form when the rapture reaches the solution surface and the second column extend cautiously from the first rapture and stick to the surface of one another as the reaction progresses. Flower shapes result from the constant replication of the inflated rapture of the surface structure under the rapid influence. The process of formation is rather intermittent and not continuous. The variation in the orientation of the reaction front does not affect the development of flower structures. Their vertical structures have clear organizations that are easy to replicate in the solution. A complex metal salt solution calcium silicate has no role to play in their formation of spiral stands and flower structures (Evdokimov, 2012).

5.12           Spiral and Roses

Once the column develops on the surface, silicate replacement occurs from the lower section of the structure of the portion, not in contact with the surface continues to grow and become less elastic. In the case of column development, the process of rapture occurs in the lower section where the rate of precipitation is low, and the crystal is brittle. As the column approaches the surface of the solution, it doesn’t rapture, but expands along the surface.  The result is the development of spirals in the solution that expand around the source of the solution. The solutions that generate internal structures similar to the column undergo elastic growth and produce of stable structural deposits structures referred to as spiral roses. Initially transparent deposits advances and become opaque as deposition progress. The resultant spiral may be either clockwise or anticlockwise, and the blossoms may exhibit radial symmetry with irregular fracturing pattern (Davis & Edwards, 2014). The spiral deposition may advance to a critical radius where the membrane loses stability, and the trapped solution may diffuse and allow radial growth of fingering structures on the outer sections.

5.13          Periodic Petal Structure

The occurrence of regular pedalling structure progresses at the surface result in thin and translucent sections. The process results from the mass transfer of particles as the solution moves from the regions with high affinity generated by surface tension differences. Further reactions in the solution alter the pH and increases the rate of precipitate solubility hence facilitate the development of ridges. The primary reaction front is the dynamic process regulates the development of observable fingers under mass transport of precipitates in the solution.  As the process advances the resultant columns add more layers and become thicker then losses their smooth ceramic appearance. Extraction of the precipitate from the solution makes the thin sections of the precipitate structure become brittle and breaks up easily (Masuda, Higashitani & Yoshida, 2007).

5.14          Viscous Fingering Structures

The structure occurs regardless of the behavior of the inner membrane and the growth progresses in as radial and symmetrical way without disruption of surface tension. The structures are qualitatively similar during viscous flow (Gai, & Boyes, 2013).

5.15          Vine Structures

The vines are linear precipitates structures that develop from specified metal salt solutions. They usually emerge from the conduits for pumped solution to the attached tubes. The liquid solution is visible in the vine image. The formation of vines involves advanced hydroxides compared to silicate solutions (Caruso, 2010).

6.0               Application of Metal Salt Solutions Structural Precipitate

The application of precipitation and crystallization principles is in municipal water and sewage treatment plants. The injection of aluminum hydroxides coagulates impurities and precipitates in the form of scrums that floats and leaves clear water that passes through to other treatment chambers for further treatment.  Next, industrial purification of sugar relies on precipitation process where the injection of sulfur in the slurry and through heating sugar paste, the residues, and other impurities can float in the heating chamber since the presence of sulfate ions possess the ability to coagulate the dirt existing in the sugar paste then precipitate forming scams.  The precipitation concept of metal salt structure helps the pharmaceutical industry in formulation drug precipitation (Lantelme & Groult, 2013). Drug extract solution is presented in larger pans and subjected to heat, then allowed to cool and separate from crystal composition. The process reduces the overall production cost while maintaining recommended produce purity.

Extraction of pure metals in the industrial sector adopts the principle of structural precipitation of compounds to retrieve a pure metal component of the solution. The industry has experienced increased trend in the application of precipitation and coagulation of solutions to separate compounds based on structural differences in the material. The method has grown to advanced stage due to the increased demand of pure substances (Funke, 2011). The faster rate, at which separation of compounds occurs through precipitation and crystallization, increases their demand in areas where the process of impurity separation needs to be faster to accommodate other processes.  Massive purification of large volumes of the solution has gained an increased adoption in domestic and industrial sectors.

7.0              Sources of Error

The projected sources of error involved in the investigation of the precipitation of metal salts to generate complex structures are diverse and originate from an instrument or inherent uncertainty. In the process of injection of calcium chloride solution, uncontrolled administration of disproportional dose of sodium silicate solution affects the concentration and performance as well as the outcome. The dosage of sodium silicate solution may exceed the recommended limit, hence; influence the rate of precipitation significantly. The error may result from the occurrence of pumping rate of calcium chloride solution. The observation of pump units in mL/hr compares to pumping speed determined through calculation and trial on the volume of solution to precipitate bore some variation that exaggerated the error in calculations. The graph of pumping vs. discharge applies the best line of fit of the plotted data created uncertainty differences (Ebbing & Gammon, 2011).

The pump presents critical deviation in data accuracy; therefore, the quantification of solutions during the precipitation and in the entire process produces false values. The error may emerge in the process of surface tension determination process through variation in the measurement of submerged tubes heights present in the distilled water maintained at low pressure. Such differences showed inaccuracy in the overall analysis of the effect of surface tension on the crystallization process of metal salts to produce complex structures.  The occurrence of scaling during crystal formation affected the structure of salts that resulted in the precipitation reaction. Such cases severely affected the performance and analysis of the resultant metal structures throughout the study. Membrane degradation lowers the performance and integrity of the developed structures (Desbene & Giorgi-Renault, 2012).  Possible causes of membrane degradation are the effect of oxidizing chemicals in the solution and the presence of heavy metals in the solution increases membrane degradation

7.1              Retardation of the Impact of Error

Limitation of error is important in ensuring the integrity of research findings. Adoption of a different approach to error mitigation depended on the nature and source of the error. The reduction of scaling involved the inclusion of acid dosing that shifts the chemical equilibrium of chemical reaction thus accelerates the rate of dissolution of salt since the added acid will lower the pH of the solution below the saturation point.  Apply antiscalant that limits scale formation by inhibiting salt from attaining a saturation, threshold, crystal modification or dispersion is essential through the addition of either organic or inorganic phosphates the solution. Reduction of membrane degradation effect is through the important design of the precipitation system. Adoption of pump flow calibration adjustments retards the severity in data dispersion at the same time improves the accuracy of data obtained in the process of discharge addition. The use of correction factors for the data involving more samples in the analysis present sizeable data that allow adoption of averages in the determination of the outcome is relevant. In the case of uncertainty attributed to surface tension the use of low-pressure system while making overall analysis limits the threat exposure noted in the structural investigations (Barke, Hazari & Yitbarek, 2009).

8.0              Conclusion

The formation of the amorphous solution produced metal salt structures through crystallization and precipitation process of calcium silicate gave compound metal coagulants of distinct structures based on the concentration, type of metal salt used in every test, saturation of ions. The temperature of the solution during crystallization constitutes critical parameters that dictate the nature of the structure of metal salts formed through precipitation processes. Involvement of experimental methods in the structural analysis is essential and advances the study of chemical processes expands the understanding of the learner about the chemical composition of solutions. The understanding of precipitation and the entire process of metal salt structure extraction increases the understanding of the students thus limits the transition challenges from institution to industrial environments based on willfully gain insight and hands-on application of the precipitation process.  The products that undergo crystallization generate distinct structures that help during separation of compounds. The knowledge of structural geometry attributed to the nature of crystallization temperatures and metal type helps with separation of compounds to obtain pure substances that result from such precipitates. The use of sodium solutions salts to form calcium silicate whose precipitation occur at elevated pH and excess silicate accelerates the pace of crystallization and precipitation processes.

The experimental evaluation of colloid formation indicates that the polymers with high pH have shorter chain lengths compared to the polymer without calcium component. The presence of calcium in the salt solution initiates amorphous silicate polymerization due to their high current ratio. Neutralization of anion charge with the addition of divalent cation produces monomers and oligomer of deprotonated silica that interacts with calcium silicate ions. The existence of antiscalants in the solution deters the formation of calcium silicate compounds while they offer limited deterrence on the calcium silicate salt precipitation or silica polymerization under increased concentration of cations. Formation of calcium silicate salt precipitate shows the existence of ionic interaction of calcium and silicate. Identification of crystalline structures of metal salt involves the use of color codes of the resultant structures.  The inclusion of catalyst during precipitation accelerates the pace of coagulation and particle growth to definite structures.

The increased analysis of the existing complex structures of metal salt solutions reveals the existence of self-assembled chemical gardens like the corals and other substances that result from the injection of catalytic in a confined geometry. The understanding of the process of crystallization improves the students’ ability to evaluate the hydrodynamics and crystal growth mechanics that generate complex metal salt structures as well as their microarchitecture. The concept of phase transformation decisively helps in the analysis of metal salt structural build up since the rate of solubility and bond dictate the packing trends adopted by the resulting molecules during precipitation of salts. Advanced analysis of the performance of salt solution about temperature, pressure and solvent stresses provide an optimal environment for establishing clear structures that emerge from the precipitate crystallization process. The inclusion of fluid flow idea during precipitation and crystallization produces distinct structures depending on the solution concentration, and the information acquired compliment the tips applicable to chemical garden developments.

The replicability of experimental data further confirms the relevancy of the process necessary while conducting detailed analysis relating to structure formation at different stages and with a different set of reagent and metal solutions. The process of structure formation at low doses of calcium metal salts produces sufficient charge neutralization through destabilization of colloidal particles. The solutions kept at the low concentration result in reduced coagulation activity, thus generate imperfect structures that are a little while at higher doses of coagulant facilitate bulk precipitation of metal hydroxides that produce larger structures. Increased application of the sweep flocculation presents the environment that facilitates impurity removal. The action of preheated coagulation ensures faster attainment of crystallization level compared to cases where the coagulant doesn’t undergo preheating. In other cases, the inclusion of organic matter or amorphous hydroxides are significant, though requires higher values of coagulant dosage at the same time rely on the pH of the surrounding solution.

9.0              Feature Work

Wholesome analysis of the compound structures resulting from metal salt solutions under the method of crystallization and precipitation requires improvements in the basic programs that are necessary and relevant to reaching the report objectively.

9.1              Structural Precipitation

Intensive work is critical in establishing the best options for qualitative analysis procedures of complex structures of metal salt obtained through precipitation and crystallization processes under varying conditions that involve distinct processes. The concentration of chloride and silicate salts exhibit different precipitation conditions. The need for the establishment of the precise structural outcome of every salt acted upon at a pacified concentration, temperature, and pressure as well as the reagent applied is essential is eliminating the persistent disparity in the system (Gai, & Boyes, 2013).

9.2              Inclusion of Tracker Software

The desire to restrain the observed shapes and patterns of structural images resulting from specific observation and action is relevant. The software facilitates quick determination of separation distance of bands from one surface to the next the establishment of a center of precipitation is essential and gives insight regarding the centers of precipitates and their edge limits. Technology that incorporates MATLAB provides critical information relating to the formation of crystalline structures of the calcium metal salts selected for analysis (Remington & Behringer, 2006).  The full adoption of visual analysis software and MATLAB in feature works is critical.

9.3              Temperature Related Effect

The expansion and growth of precipitates tend to drift to the region of the higher silicate solution. The increase in temperature of solution generates structural patterns that cause the growth of precipitate crystals. Further effort is necessary for establishing the trends of selective crystallization under localized temperature differences in the solution (Barke, Harsch, & Schmid, 2012).   Fluctuation in solution temperature from cold to warm confines structure formation at known rates, thus the need to change the methods used are an essential mark to attain improved performance in advancing the study of metal salt crystalline structures.

9.4              Surface Tension Analysis

Replication of methods utilized in the determination of capillarity radius during metal structural analysis should adopt the use of silicate or chloride solution as a replacement of distilled water. The procedural application of equation to establish the value of capillary radius while using the known values of maximum possible pressure due to the known surface tension of distilled water   (Lantelme & Groult, 2013). The establishment of pressure value as the tube contained air and submerged to different levels adopts the bubble pressure method that is more reliable and sustaining compared to other means of a surface tension establishment process for the resulting metal precipitates.

9.5              Chemical Analysis

The chemicals used throughout precipitation and structural analysis rely on the scanned images processed by microscopic cameras. Determination of the performance of metal structure formation under the influence of varied quantities of carbonate and silicate through chemical characterization is an essential consideration for future investigation. Review of the chemical stability of the structure generated is significant since the oxidation of developed structures once exposed to the free atmosphere for observation alters their stability and final analysis. For the plastic structure, the deformation characteristic presents the structure to unclear bonding forces that affect the overall appearance of the structure (Ebbing & Gammon, 2011). The morphology of crystals has a significant effect on the chemical structures resulting from the total precipitation of calcium salt solution.

9.6              Involvement of IR Cameras

Establishment of precipitation temperatures is essential as it influence the advancement of retarded crystal growth from the solution at the top layer attributed to higher temperatures due to conventional heat flow pattern in the fluid. The formation of the crystalline structure is null at the top layer of the solution marked with increased temperatures at the initial stages. The images from the camera of the molten layer presented in temperature color codes sustain temperature comparison at different layers in the solution (Haudin, Cartwright, Brau & De Wit, 2014; Allcock, 2008).  The increasing adoption of IR camera in capturing images of continuous processes reduces the time taken in data collection and provides relatively accurate information about structures developed during precipitation of salts.  The level of accuracy attained with IR cameras accelerates their adoption in feature studies in conformity to technological advancements.






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