scholarly journals Obtaining artificial carnallites from magnesium chloride brines

2020 ◽  
Vol 56 (2) ◽  
pp. 229-234
Author(s):  
V. V. Shevchuk ◽  
T. N. Potkina ◽  
A. I. Vaitenka ◽  
O. V. Smetanina
Keyword(s):  
Calcium Chloride ◽  
Magnesium Chloride ◽  
Calcium Sulfate ◽  
Raw Materials ◽  
Potassium Sulfate ◽  
Sulfate Ions ◽  
Chloride Solutions ◽  
Excess Concentration ◽  
Almost All ◽  
Complete Precipitation

The excess of magnesium chloride brines is formed during the polymineral ores processing in order to obtain potassium sulfate. One way to regenerate such brines is to produce artificial carnallite. It is necessary to purify these brines from sulfates for their further use as raw materials for the artificial carnallite production. In this work, the process of desulfurization of magnesium chloride brines with a solution of calcium chloride is studied. The temperature and the processing time, the magnesium chloride solutions concentration and the consumption of desulfurizing agent (calcium chloride) influence on the degree of magnesium chloride solutions purification from sulfate ions was determined. It has been established that almost all sulfate ions interact with calcium ion in 15 minutes and the desulfurization degree reaches 98,08 %. The increase in duration of the suspension mixing is necessary in order to establish equilibrium in the system and relieve the supersaturation in the solution. It has been shown that with increasing solutions saturation with MgCl2, the degree of the magnesium chloride brines purification from SO4 2– ion increases. Complete precipitation of calcium sulfate requires a certain excess concentration of calcium chloride.

Leaching kinetics of lead from lead (II) sulphate in aqueous calcium chloride and magnesium chloride solutions

1997 ◽  
Vol 47 (1) ◽  
pp. 137-147 ◽  
Author(s):  
Dragan Sinadinović ◽  
Željko Kamberović ◽  
Aleksandar Šutić
Keyword(s):  
Calcium Chloride ◽  
Magnesium Chloride ◽  
Leaching Kinetics ◽  
Chloride Solutions ◽  
Kinetics Of

Novel attempts for the synthesis of calcium sulfate hydrates in calcium chloride solutions under atmospheric conditions

2012 ◽  
Vol 38 (1) ◽  
pp. 381-387 ◽  
Author(s):  
Jen-Chang Yang ◽  
Hong-Da Wu ◽  
Nai-Chia Teng ◽  
Dian-Yu Ji ◽  
Sheng-Yang Lee
Keyword(s):  
Calcium Chloride ◽  
Calcium Sulfate ◽  
Atmospheric Conditions ◽  
Chloride Solutions

Effects of sterilization modes on the mechanical strengths of plaster of paris implants

1989 ◽  
Vol 47 ◽  
pp. 890-891
Author(s):  
K. Cowden ◽  
B. Giammara ◽  
T. Devine ◽  
J. Hanker
Keyword(s):  
Gamma Radiation ◽  
Calcium Sulfate ◽  
Significant Loss ◽  
Potassium Sulfate ◽  
Limiting Factors ◽  
Radiation Sterilization ◽  
Plaster Of Paris ◽  
Hardness Tester ◽  
Dry Heat ◽  
Calcium Sulfate Hemihydrate

Plaster of Paris (calcium sulfate hemihydrate, CaSO4. ½ H2O) has been used as a biomedical implant material since 1892. One of the primary limiting factors of these implants is their mechanical properties. These materials have low compressive and tensile strengths when compared to normal bone. These are important limiting factors where large biomechanical forces exist. Previous work has suggested that sterilization techniques could affect the implant’s strength. A study of plaster of Paris implant mechanical and physical properties to find optimum sterilization techniques therefore, could lead to a significant increase in their application and promise for future use as hard tissue prosthetic materials.USG Medical Grade Calcium Sulfate Hemihydrate Types A, A-1 and B, were sterilized by dry heat and by gamma radiation. Types A and B were additionally sterilized with and without the setting agent potassium sulfate (K2SO4). The plaster mixtures were then moistened with a minimum amount of water and formed into disks (.339 in. diameter x .053 in. deep) in polyethylene molds with a microspatula. After drying, the disks were fractured with a Stokes Hardness Tester. The compressive strengths of the disks were obtained directly from the hardness tester. Values for the maximum tensile strengths σo were then calculated: where (P = applied compression, D = disk diameter, and t = disk thickness). Plaster disks (types A and B) that contained no setting agent showed a significant loss in strength with either dry heat or gamma radiation sterilization. Those that contained potassium sulfate (K2SO4) did not show a significant loss in strength with either sterilization technique. In all comparisons (with and without K2SO4 and with either dry heat or gamma radiation sterilization) the type B plaster had higher compressive and tensile strengths than that of the type A plaster. The type A-1 plaster however, which is specially modified for accelerated setting, was comparable to that of type B with K2SO4 in both compressive and tensile strength (Table 1).

Microbiological analysis of popular spreads used in restaurants inside Dhaka city, Bangladesh

2020 ◽  
Vol 10 (1) ◽  
pp. 16-19
Author(s):  
Tasnia Ahmed ◽  
Md Aftab Uddin
Keyword(s):  
Raw Materials ◽  
Peanut Butter ◽  
Food Additives ◽  
Microbiological Analysis ◽  
Dhaka City ◽  
Acceptable Result ◽  
Fast Foods ◽  
Public Consumption ◽  
Viable Bacteria ◽  
Almost All

Spreads are used widely for making the fast foods more amazing and tasty. Varieties and cross combinations of ingredients are used to make many flavours of fast foods. Different restaurants prepare their signature spreads for attracting people but this can cause opposite result if not prepared using high quality raw materials and proper hygienic conditions are not maintained. Current study was conducted on ten different types of spreads (pesto, cilantro, queso, tomato sauce, peanut butter, honey, mustard, cream cheese, chocolate sauce and butter) which are used by the local restaurants in Dhaka city, Bangladesh. Almost all the samples (nine out of ten) harbored total viable bacteria exceeding the standard limit. Four spread samples showed high fungal count (102 cfu/gm). Four samples showed to be positive (˃101/ml recommended acceptable count) for Escherichia coli and Klebsiella spp. which indicates that these spread cannot be recommended for public consumption. Among all the samples examined, only chocolate sauce showed acceptable result without the presence of coliforms, Staphylococcus spp. and Pseudomonas spp. This finding suggests proper maintenance of sanitation in spread preparation and selling area. A proper guidelines and monitoring can help keep up the quality of food additives. Stamford Journal of Microbiology, Vol.10 (1) 2020: 16-19

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