Efficient separation of silica and alumina in simulated CFB slag by reduction roasting-alkaline leaching process

2019 ◽  
Vol 87 ◽  
pp. 798-804 ◽  
Author(s):  
Xiaobin Li ◽  
Hongyang Wang ◽  
Qiusheng Zhou ◽  
Tiangui Qi ◽  
Guihua Liu ◽  
...  
Keyword(s):  
Reduction Roasting ◽  
Alkaline Leaching ◽  
Efficient Separation ◽  
Leaching Process

scholarly journals Effect of Na2Co3 on the preparation of metallic tin from cassiterite roasted under strong reductive atmosphere

2016 ◽  
Vol 52 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Y. Zhang ◽  
B. Liu ◽  
Z. Su ◽  
J. Chen ◽  
G. Li ◽  
...  
Keyword(s):  
Raw Materials ◽  
Water Solution ◽  
Pure Sno2 ◽  
The Novel ◽  
Reduction Roasting ◽  
Water Leaching ◽  
Leaching Process ◽  
Roasting Process ◽  
Reductive Atmosphere ◽  
The Impact

Tin is an indispensable metal in the modern industry. The current tin smelting processes, however, have the disadvantages of high smelting temperature, long smelting time, especially high tin loss ratio (>10 wt%). The tin loss attributes to the volatilization as gaseous SnO and stannous silicate (SnO?SiO2) residual in the slag. An innovative approach for preparing metallic tin effectively from cassiterite in the presence of Na2CO3, named gas-based reduction roasting followed by water leaching process, is under development in Central South University, China. The present study, using chemically pure SnO2 and SiO2, aims to determine the impact of Na2CO3 on the metallic tin preparation from cassiterite by the novel process using XRD, SEM-EDS, chemical analysis, etc. It was found that Na2CO3 effectively restrained the tin volatilization as SnO and the formation of hardly reductive SnO?SiO2 during the reduction roasting process. In the presence of Na2CO3, most of SnO2 in the raw materials (mixture of SnO2+SiO2) was directly reduced to metallic tin, and part of SnO2 reacted with Na2CO3 to form intermediate Na2SnO3, which was then reduced to metallic tin. The SiO2 was transformed into Na2SiO3 and then went into the water solution in the following water-leaching process. The main reactions of the SnO2 + SiO2 system in the presence of Na2CO3 under reductive atmosphere were ascertained.

scholarly journals PROCESSING OF ZAGLIK ALUNITE ORE BY HEAP AND TANK LEACHING

2021 ◽  
pp. 42-49
Author(s):  
A.A. Heydarov ◽  
◽  
Ch.M. Kashkai ◽  
Keyword(s):  
Weight Loss ◽  
Heap Leaching ◽  
Alkali Solution ◽  
Alkali Concentration ◽  
Alkaline Leaching ◽  
Leaching Process ◽  
Liquid Phases ◽  
Naoh Solution ◽  
First Time

The present work is continuation of our investigations on heap leaching, suggested for the first time. Various variants of alkaline leaching of alunite from alunite ore without preliminary roasting have been studied. In present work the parameters of heap and tank alkaline leaching of alunite ore have been determined. The proposed methods can also be used to extract aluminum from poor alunite rocks. At alunite was washed 17 times with 3% NaOH solution, the degree of weight loss was 30.65%, while with 14 times washing with 10% alkali solution, the weight loss was 47.82 %. The results obtained are also typical for percolation leaching. An increase in alkali concentration and temperature intensifies the leaching process. At a ratio of solid and liquid phases of 1:5, a stirring speed of – 700 cycles/min, and an alkali concentration of 110.9 g/l, at 800C within 60 minutes’ alunite dissolves up to 96% and goes into solution with accompanying components

scholarly journals Selective Pre-leaching of Tellurium From Telluride-Type Gold Concentrate

2021 ◽  
Vol 9 ◽  
Author(s):  
Wei Yang ◽  
Xuechen Lan ◽  
Qian Wang ◽  
Ping Dong ◽  
Gang Wang
Keyword(s):  
Noble Metals ◽  
Diffusion Control ◽  
Leaching Rate ◽  
Rare Element ◽  
Alkaline Leaching ◽  
Flotation Concentrate ◽  
Solid Ratio ◽  
Leaching Process ◽  
New Ideas ◽  
And Diffusion

With a telluride-type gold ore flotation concentrate as the research object, the Na2S + NaOH collaborative leaching process was applied to selectively separate tellurium before the cyanide leaching of gold and silver. The effects of process parameters including the type of leaching agent, the amount of leaching agent, liquid-solid ratio, leaching temperature, and leaching time on the leaching rate of tellurium were investigated. The results showed that the tellurium leaching rate could reach 78.14% under the optimum conditions of −0.038 mm (95%) grinding fineness, 80 g/L Na2S concentration, 30 g/L NaOH concentration, 4:1 liquid-solid ratio, 80°C leaching temperature and 3 h′s leaching time. The kinetic analysis showed that the leaching process of tellurium from telluride-type gold concentrate was a mixed type of chemical reaction control and diffusion control. The grain parameter in the leaching process was 0.26263 and the apparent activation energy E = 17.12 kJ/mol. Tellurium could be pre-leached from the telluride-type gold flotation concentrate through the Na2S + NaOH alkaline leaching process to achieve the effective separation of tellurium from noble metals, which, when eliminating the adverse effects of telluride on the leaching of gold and silver, provides new ideas for the extraction of rare element tellurium.

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