scholarly journals Removal of cobalt and nickel from zinc sulphate solutions using activated cementation

2004 ◽  
Vol 40 (1) ◽  
pp. 41-55 ◽  
Author(s):  
B. Boyanov ◽  
V. Konareva ◽  
N. Kolev
Keyword(s):  
Great Degree ◽  
Zinc Sulphate ◽  
Zinc Dust ◽  
Lower Degree ◽  
Production Plant ◽  
Optimal Conditions ◽  
Zinc Production ◽  
Cobalt And Nickel

The influence of different parameters (duration, temperature, zinc dust quantity, concentration of activators - copper and antimony) on the process of activated cementation of Co and Ni has been studied. We have worked with industrial zinc sulphate solutions. During the process of activated cementation of Co and Ni, copper (involved as CuSO4.5H2O) and antimony (involved as Sb2O3) were used as activators. The lowest values of Co content have been obtained at a temperature of 80-85 oC, CCu = 200-300 mg/dm3 and 18 multiple surplus of zinc dust. After adding Cu to the solution, mainly the cementation of Ni is activated, and that of Co is activated to a lower degree. It was found that when GSb : GCo ratio is between 0.5 : 1 and 2 : 1, the solution is purified from Co and Ni to a great degree. After intensive stirring and increasing the duration of the process the cement sediments dissolve reversely. This holds true of Co to a greater extent, as compared to Ni. The results obtained will be used to establish optimal conditions for the carrying out of activated cementation in Zinc Production Plant in KCM SA, Plovdiv.

Analysis and Optimization of a Zinc Production Plant

1983 ◽  
Vol 16 (12) ◽  
pp. 423-429
Author(s):  
M. Deleris ◽  
A. Titli
Keyword(s):  
Production Plant ◽  
Zinc Production

Hybrid fuzzy control for the goethite process in zinc production plant combining type-1 and type-2 fuzzy logics

2019 ◽  
Vol 366 ◽  
pp. 170-177 ◽  
Author(s):  
Shiwen Xie ◽  
Yongfang Xie ◽  
Fanbiao Li ◽  
Zhaohui Jiang ◽  
Weihua Gui
Keyword(s):  
Fuzzy Control ◽  
Production Plant ◽  
Fuzzy Logics ◽  
Zinc Production

Influencing Factors and Mechanism of Cobalt Redissolution from Zinc Sulphate Solution

2011 ◽  
Vol 402 ◽  
pp. 12-16 ◽  
Author(s):  
Gui Sheng Zeng ◽  
Ming Jing Li ◽  
Yu Xie
Keyword(s):  
Particle Size ◽  
Influencing Factors ◽  
Zinc Sulphate ◽  
Zinc Dust ◽  
Copper Ion ◽  
Sulphate Solution ◽  
Detention Time ◽  
Large Particles ◽  
Zinc Sulphate Solution

Redissolution of cemented cobalt from zinc sulphate solution occurs, and is a well known problem among zinc producers. A variety of mechanism of cobalt redisisolution have been proposed in the literatures, however, it is still not very well understood. The influencing factors of cobalt redissolution such as detention time, oxidation, particle size of zinc dust and copper ion have been investigated in this paper. The redissolution does not occur when very large particles are used but the redissolution of cobalt is significant from small zinc particles. The redissolution is obvious with copper ion added, while the redissolution is not occurred from the zinc sulphated solution without copper ion added. The redissolution mechanism of cobalt is obtained.

Amorphous silica coating on α-alumina particles

1995 ◽  
Vol 53 ◽  
pp. 210-211
Author(s):  
J. W. Mellowes ◽  
C. M. Chun ◽  
I. A. Aksay
Keyword(s):  
Amorphous Silica ◽  
Heterogeneous Nucleation ◽  
Homogeneous Nucleation ◽  
Silica Coating ◽  
Full Density ◽  
Optimal Conditions ◽  
Fine Grained ◽  
Alumina Particles ◽  
Complete Mullitization ◽  
Powder Compacts

Mullite (3Al2O32SiO2) can be fabricated by transient viscous sintering using composite particles which consist of inner cores of a-alumina and outer coatings of amorphous silica. Powder compacts prepared with these particles are sintered to almost full density at relatively low temperatures (~1300°C) and converted to dense, fine-grained mullite at higher temperatures (>1500°C) by reaction between the alumina core and the silica coating. In order to achieve complete mullitization, optimal conditions for coating alumina particles with amorphous silica must be achieved. Formation of amorphous silica can occur in solution (homogeneous nucleation) or on the surface of alumina (heterogeneous nucleation) depending on the degree of supersaturation of the solvent in which the particles are immersed. Successful coating of silica on alumina occurs when heterogeneous nucleation is promoted and homogeneous nucleation is suppressed. Therefore, one key to successful coating is an understanding of the factors such as pH and concentration that control silica nucleation in aqueous solutions. In the current work, we use TEM to determine the optimal conditions of this processing.

Use of digital microscopy in process control during the manufacture of rubber-modified thermoplastics

1996 ◽  
Vol 54 ◽  
pp. 616-617
Author(s):  
M. T. Dineen
Keyword(s):  
Ccd Camera ◽  
Operating Costs ◽  
Hard Copy ◽  
Production Plant ◽  
Digital Microscopy ◽  
Nih Image ◽  
Transmission Electron ◽  
Conventional Film ◽  
Product Loss ◽  
Image Collection

The production of rubber modified thermoplastics can exceed rates of 30,000 pounds per hour. If a production plant needs to equilibrate or has an upset, that means operating costs and lost revenue. Results of transmission electron microscopy (TEM) can be used for process adjustments to minimize product loss. Conventional TEM, however, is not a rapid turnaround technique. The TEM process was examined, and it was determined that 50% of the time it took to complete a polymer sample was related to film processing, even when using automated equipment. By replacing the conventional film portion of the process with a commercially available system to digitally acquire the TEM image, a production plant can have the same TEM image in the control room within 1.5 hours of sampling.A Hitachi H-600 TEM Operated at 100 kV with a tungsten filament was retrofitted with a SEMICAPS™ image collection and processing workstation and a KODAK MEGAPLUS™ charged coupled device (CCD) camera (Fig. 1). Media Cybernetics Image-Pro Plus software was included, and connections to a Phaser II SDX printer and the network were made. Network printers and other PC and Mac software (e.g. NIH Image) were available. By using digital acquisition and processing, the time it takes to produce a hard copy of a digital image is greatly reduced compared to the time it takes to process film.

Immunocytochemical methodology for the localization of neuronal antigens at the ultrastructural level

1990 ◽  
Vol 48 (3) ◽  
pp. 876-877
Author(s):  
Jorge Pecci Saavedra ◽  
Mark Connaughton ◽  
Juan José López ◽  
Alicia Brusco
Keyword(s):  
Spinal Cord ◽  
Substantia Nigra ◽  
Polyclonal Antibodies ◽  
Ultrastructural Level ◽  
Point Of View ◽  
Nerve Tissue ◽  
Tissue Fixation ◽  
Optimal Conditions ◽  
Interpeduncular Nucleus ◽  
Technical Point

The use of antibodies as labels for the localization of specific molecules in the nervous systan has been extensively applied in recent years. Both monoand polyclonal antibodies or antisera have been employed. The knowledge of the organization of neuronal connectivities, gliovascular relationships, glioneuronal relationships and other features of nerve tissue has greatly increased.A number of areas of the nervous systan have been analyzed in our laboratory, including the nuclei of the raphe system, the reticular formation, interpeduncular nucleus, substantia nigra, caudate nucleus, putamen, pallidum, spinal cord, pineal gland and others.From a technical point of view, a number of variables needed to be taken into account in order to obtain reliable and reproducible results. The design of the optimal conditions of tissue fixation, embedding, sectioning, dilution of antibodies, and adaptation of Sternberger PAP technique were sane of the parameters taken into account to optimize the results. It is critical that each step of the technique be defined for each particular case.

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