scholarly journals The study of compositions based on parkent kaolin clay

2018 ◽  
pp. 29-33
Author(s):  
M. Kh. Rumi ◽  
Sh. K. Irmatova ◽  
M. A. Zufarov ◽  
Sh. A. Fayziev ◽  
E. P. Mansurova ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Liquid Glass ◽  
Calcium Sulfate ◽  
Kaolin Clay ◽  
Acid Activation ◽  
Kaolinite Clay ◽  
Aluminum Ions ◽  
Heat Treated ◽  
Rate Of Extraction ◽  
Subsequent Acid

The results of studies of the structure and composition of compositions based on red-burning kaolinite clay and calcium carbonate, heat-treated at 500oC, in the process of acid activation are presented. It is shown that when a 12 % solution of H2SO4is applied, leaching of iron and aluminum ions and the formation of calcium sulfate occur while maintaining the structure of kaolinite. The introduction of liquid glass into the composition of the material leads to the destruction of the structure of kaolinite, which contributes to an increase in the rate of extraction of aluminum ions during the subsequent acid activation. The components of the compositions with Ca2+and Fe3+in the presence of liquid glass are passivated by active amorphous silica formed during the reaction of liquid glass with CO2air.Ill. 2. Ref. 17. Tab. 1.

scholarly journals Elucidation of Gram-Positive Bacterial Iron(III) Reduction for Kaolinite Clay Refinement

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3084
Author(s):  
Hao Jing ◽  
Zhao Liu ◽  
Seng How Kuan ◽  
Sylvia Chieng ◽  
Chun Loong Ho
Keyword(s):  
Iron Reduction ◽  
Growth Conditions ◽  
Cellular Interaction ◽  
Kaolin Clay ◽  
Media Composition ◽  
Gram Positive ◽  
Kaolinite Clay ◽  
Gram Positive Bacteria ◽  
Rich Media ◽  
The Media

Recently, microbial-based iron reduction has been considered as a viable alternative to typical chemical-based treatments. The iron reduction is an important process in kaolin refining, where iron-bearing impurities in kaolin clay affects the whiteness, refractory properties, and its commercial value. In recent years, Gram-negative bacteria has been in the center stage of iron reduction research, whereas little is known about the potential use of Gram-positive bacteria to refine kaolin clay. In this study, we investigated the ferric reducing capabilities of five microbes by manipulating the microbial growth conditions. Out of the five, we discovered that Bacillus cereus and Staphylococcus aureus outperformed the other microbes under nitrogen-rich media. Through the biochemical changes and the microbial behavior, we mapped the hypothetical pathway leading to the iron reduction cellular properties, and found that the iron reduction properties of these Gram-positive bacteria rely heavily on the media composition. The media composition results in increased basification of the media that is a prerequisite for the cellular reduction of ferric ions. Further, these changes impact the formation of biofilm, suggesting that the cellular interaction for the iron(III)oxide reduction is not solely reliant on the formation of biofilms. This article reveals the potential development of Gram-positive microbes in facilitating the microbial-based removal of metal contaminants from clays or ores. Further studies to elucidate the corresponding pathways would be crucial for the further development of the field.

Viability of Acid-Adapted Escherichia coli O157:H7 in Ground Beef Treated with Acidic Calcium Sulfate

2004 ◽  
Vol 67 (3) ◽  
pp. 591-595 ◽  
Author(s):  
LARRY R. BEUCHAT ◽  
ALAN J. SCOUTEN
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Calcium Sulfate ◽  
Ground Beef ◽  
Storage Period ◽  
Acid Tolerance ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Acidic Environments ◽  
Subsequent Acid

The effects of lactic acid, acetic acid, and acidic calcium sulfate (ACS) on viability and subsequent acid tolerance of three strains of Escherichia coli O157:H7 were determined. Differences in tolerance to acidic environments were observed among strains, but the level of tolerance was not affected by the acidulant to which cells had been exposed. Cells of E. coli O157:H7 adapted to grow on tryptic soy agar acidified to pH 4.5 with ACS were compared to cells grown at pH 7.2 in the absence of ACS for their ability to survive after inoculation into ground beef treated with ACS, as well as untreated beef. The number of ACS-adapted cells recovered from ACS-treated beef was significantly (α = 0.05) higher than the number of control cells recovered from ACS-treated beef during the first 3 days of a 10-day storage period at 4°C, suggesting that ACS-adapted cells might be initially more tolerant than unadapted cells to reduced pH in ACS-treated beef. Regardless of treatment of ground beef with ACS or adaptation of E. coli O157:H7 to ACS before inoculating ground beef, the pathogen survived in high numbers.

scholarly journals Research of nanostructural minerals – bentonites used in purification of mineral water from heavy metal ions (Cu2+, Pb2+, Cd2+, Zn 2+)

2020 ◽  
Vol 4 (78) ◽  
pp. 115-122
Author(s):  
A. SH. BUKUNOVA ◽  
◽  
G. ZH. TURSBEKOVA ◽  
L. B. IRISKINA ◽  
M. K. ZHAMANBAEVA ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Mine Water ◽  
Heavy Metal Ions ◽  
Structural Characteristics ◽  
Mining Industry ◽  
Bentonite Clay ◽  
Acid Activation ◽  
Exchange Cations ◽  
Aluminum Ions

This paper presents the results of studies on the use of bentonite from the Taganskoye field for purification of mine water from the mining industry from heavy metal ions (MI). It has been established that the use of the thermo-acid-activated form of bentonite clay allows the removal of MI Cu2+, Pb2+, Cd2+, Zn2+ions from mine water by 99.6, 94.7, 98.9, 99.5 %, respectively, which ensures that the maximum permissible concentration of fishery is achieved at selected optimal conditions that were identified on the basis of an active experiment. A comparative analysis of the presented results of mass spectrometry and scanning electron microscopy shows that they are valid and do not contradict the obtained experimental data on the composition of exchange cations and structural characteristics in ultrafine mineral phases of bentonite clay samples of natural and thermo-acid activated forms It has been established that during acid activation of bentonite clays, the structure of montmorillonite is retained upon extraction of up to 80 % of magnesium, iron, and aluminum ions and is destroyed only upon their almost complete extraction.

scholarly journals First-principles study of calcium-based sulfur fixers and their products

2021 ◽  
pp. 350-350
Author(s):  
Guoyan Chen ◽  
Jianing Chen ◽  
Anchao Zhang ◽  
Haoxin Deng ◽  
Yanyang Mei ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Power Plant ◽  
Thermodynamic Properties ◽  
Calcium Oxide ◽  
First Principles ◽  
Calcium Sulfate ◽  
Density Functional ◽  
Stable State ◽  
Generalized Gradient ◽  
Calcium Sulphoaluminate

Calcium-based sulfur-fixing agent, as the main sulfur-fixing product, is widely used in power plant boiler systems. In order to further study the thermodynamic properties and reaction characteristics of calcium-based sulfur fixing agent and its products, the method of combining power plant experiment with theory was used. The electronic structure, thermodynamic properties and density of states of quicklime, limestone, calcium sulfate and calcium sulphoaluminate have been calculated based on the first-principles ultra-soft pseudopotential plane wave method of density functional theory. The generalized gradient approximation algorithm isused to optimize the structure of various minerals to achieve the most stable state. The results show that the enthalpy, entropy, specific heat capacity at constant pressure and Gibbs free energy of calcium sulfonate vary greatly from 25K to 1000K, while the change of calcium oxide is small, and that of calcium carbonate and calcium sulfate are between them. It shows that calcium sulphoaluminate has strong stability and more energy is needed to destroy the molecular structure of calcium sulphoaluminate. Calcium oxide is the most unstable and requires less energy to react; Calcium carbonate and calcium sulfate are in between. The variation range of calcium sulfate is greater than that of calcium carbonate, indicating that the stability of calcium sulfate is higher than that of calcium carbonate. The experimental results show that the desulfurization efficiency of generating calcium sulphoaluminate is much higher than that of only generating calcium sulfate, indicating that calcium sulphoaluminate is very stable, which is consistent with the calculated results.

Real-time detection of early-stage calcium sulfate and calcium carbonate scaling using Raman spectroscopy

2020 ◽  
Vol 596 ◽  
pp. 117603 ◽  
Author(s):  
Omkar D. Supekar ◽  
Danielle J. Park ◽  
Alan R. Greenberg ◽  
Juliet T. Gopinath ◽  
Victor M. Bright
Keyword(s):  
Raman Spectroscopy ◽  
Calcium Carbonate ◽  
Real Time ◽  
Calcium Sulfate ◽  
Early Stage ◽  
Real Time Detection

Analysis of Physical and Chemical Features of Sintering Dust and Study of Recycling Treatment

2015 ◽  
Vol 768 ◽  
pp. 350-362
Author(s):  
Bin Pei ◽  
Guang Zhan ◽  
Zhan Cheng Guo ◽  
Jin Tao Gao
Keyword(s):  
Calcium Carbonate ◽  
Potassium Chloride ◽  
Sodium Carbonate ◽  
Calcium Sulfate ◽  
Sodium Carbonate Solution ◽  
Potassium Sulfate ◽  
Water Leaching ◽  
Leaching Experiment ◽  
Leaching Solution ◽  
Physical And Chemical

Several physical and chemical detection methods were used to study the basic properties of sintering dust collected from Baogang Steel Corporation. The result shows that the major constituents of the electrostatic precipitator dust (ESP dust) were KCl, NaCl, Fe2O3 and Fe3O4. Water leaching experiment on the sintering dust had shown that the KCl in the ESP dust could be separated and recovered by water leaching and fractional crystallization. Component analysis of leaching solution showed that the massive calcium sulfate in the leaching solution should be removed first in order to obtain the pure potassium salt. In order to provide theoretical guidance to inhibit the dissolution of calcium ions from the sintering dust, the water leaching experiment of ESP dust and the dissolution behavior of CaSO4 in the potassium chloride, sodium chloride, potassium sulfate and their mixed salt solution were studied. Result showed that, a lower liquid-solid ratio should be chosen in the leaching process to inhibit the dissolution of calcium sulfate dehydrate. Using sodium carbonate solution as a precipitating agent, the influences of the concentration of sodium carbonate solution, reaction temperature, stirring speed on the preparation of the spherical calcium carbonate were studied. Spherical calcium carbonate with good dispersing performance and grain size distribution in nanometer range of less than 10μm was obtained. The production technology of potassium sulfate by double decomposition was sutdied, the results showed that over 80% and 12.76% of the recovery rate of potassium sulfate and potassium chloride ammonium compound fertilizer could be obtained. Furthermore, a potassium recovery process with joint production of spherical calcium carbonate and potassium sulfate was designed. This process is technically viable and considerable in economic benefit.

Design and Optimization of the Preparation of Calcium Carbonate from Calcium Sulfate and Ammonium Bicarbonate

2014 ◽  
Vol 12 (1) ◽  
pp. 611-621 ◽  
Author(s):  
Jingcai Zhao ◽  
Xingfu Song ◽  
Ze Sun ◽  
Yanxia Xu ◽  
Jianguo Yu
Keyword(s):  
Calcium Carbonate ◽  
Calcium Sulfate ◽  
Polynomial Equation ◽  
Ammonium Bicarbonate ◽  
Experimental Result ◽  
Process Conditions ◽  
Single Factor ◽  
Design And Optimization ◽  
Optimum Parameters ◽  
Factor Effect

Abstract Simulation on single factor effect was used for the design and optimization of the preparation of calcium carbonate from calcium sulfate (DH) and ammonium bicarbonate. This study shows that simulation on single factor effect is effective because the experimental results are close to predicted results. Furthermore, response surface method based on a central composite design was used to determine the range of parameters to achieve a highly efficient conversion of DH. The results indicate that the significant parameters that affected the conversion of DH were ratio of carbon to sulfur, temperature, concentration of ammonium bicarbonate, and stirring speed. The strength order of factors is as follows: ratio of carbon to sulfur > concentration of ammonium bicarbonate > stirring speed > temperature. A quadratic polynomial equation was established using multiple regression analysis. The optimum parameters were determined as follows: 2.10 for ratio of carbon to sulfur, 320.35 K for temperature, 337.31 rpm for the stirring speed, and 1.75 mol · L−1 for bicarbonate concentration. The corresponding conversion rate of the experimental result was 99.7%, which was highly consistent with the predicted value of 99.9%. Based on model and the optimum parameters, products of vaterite, with ammonium sulfate crystal of grade A, can be obtained. Equipotential lines of conversional rate and desired process conditions were provided as well.

Solidification of Greenhouse Gas Carbon Dioxide

2014 ◽  
Vol 472 ◽  
pp. 879-883
Author(s):  
Wei Yin
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Ambient Temperature ◽  
Calcium Sulfate ◽  
Exothermic Reaction ◽  
Ammonium Bicarbonate ◽  
Second Order Reaction ◽  
Carbon Dioxide Gas ◽  
Water Media ◽  
Closed Reactor

The feasible routine of carbon dioxide solidification is developed, which employs carbon dioxide with calcium sulfate and ammonia to obtain calcium carbonate and ammonium sulfate at ambient temperature. The process of carbon dioxide solidification is a spontaneous and exothermic reaction, whose possesses the rate constants of the second order reaction, which can be attributed to carbon dioxide gas dissolving the water media and carbon dioxide reacted with ammonia to produce ammonium bicarbonate. Calcium sulfate changing rapidly into calcium carbonate accelerates the process of reaction of carbon dioxide reacted with ammonia. The optimization process parameters of carbon dioxide solidification are a 0.075-MPa of CO2, a 0.5-mol of CaSO4·2H2O, a 0.5-mol of NH3·H2O and a 100-ml of H2O in a closed reactor, which is able to obtain 100% CO2 gas solidification efficiency within 4 minutes at ambient temperature.

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