YUAN Meng
,
LUO Aiqing
,
WANG Chun
,
LI Deqian (Changchun Institute of Applied Chemistry
,
Chinese Academy of Sciences
,
Changchun. China Manuscript received 7 November
,
1994)
金属学报(英文版)
Solvent extraction of trivalent lanthanides (except for Pm with Cyanex 302 [Bis (2,4,4-trimethylpentyl)monothiophosphinic acid] in heptane was studied at various aqueous pH values, extractant concentrations and different temperatures. Cyanex 302 shows pretty good behaviours on the extraction of lanthanides, especially when extracting heavy lanthanides. However,purified Cyanex 302 exhibits signi ficantly lower extractability to lanthanides than raw extractant. The roles ofdifferent components ofraw Cyanex 302 were discussed to understand the reason of good extractability of the raw extractant. The lanthanides extraction stoichiometry is discussed on the basis ofexperimental results, which can be expressed as follows:
关键词:
: Bis(2
,
null
,
null
,
null
,
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Transactions of Nonferrous Metals Society of China
A new process for the hydrometallurgy of refractory gold concentrates was presented. The process comprises grinding-leaching, intensified alkaline leaching (IAL), cyanidation and adsorption. In a stirring-type pulverizing-leaching tower mill, the concentrate is ground to <35. 6 μm of 95. 5 % while simultaneously leached by NaOH of 12 kg/t, then carried out intensified alkaline leaching for 48 h by NaOH of 108 kg/t in enhanced agitation tanks with the pulp concentration of 40% solids at the environmental temperature of 9. 5 &SIM; 13. 5 &DEG;C and the environmental pressure of 10(5) Pa. The oxidation rate of As is 94. 9%, and 47. 6% for S. The total consumption of NaOH is only 20% of that theoretically calculated under the conditions of full oxidation at the same oxidation rates of arsenic to arsenate and sulfur to sulfate. The gold leaching rate by NaCN in 24 h is increased from 9. 2% before pretreatment to 94. 2%. The consumption of NaCN is 7. 5 kg/t, which is one times less than that before pretreatment. The extraction cost of gold is about 422 Yuan/t.
关键词:
refractory gold concentrates;grinding-leaching;intensified alkaline;leaching (IAL);pretreatment;common temperature and pressure
