(1. 中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué) 稀有金屬冶金與材料制備湖南省重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 目前鎢冶煉企業(yè)廣泛應(yīng)用的除鉬方法是基于鎢鉬與硫親合力的差異，針對(duì)該方法中存在的鉬硫化劑含硫量低且價(jià)格高的問題，提出以五硫化二磷P2S5作為新型硫化劑，通過其水解產(chǎn)生硫氫根為鉬的硫化提供硫源的設(shè)想，并從熱力學(xué)角度考察P2S5在水溶液中的水解過程及鎢、鉬的硫化行為。結(jié)果表明：P2S5水解產(chǎn)生鉬硫化所需要的硫氫根；同時(shí)，在pH值7~9的弱堿性溶液中，n(S)/n(Mo)為8時(shí)，硫氫根可使溶液中的MoO42-完全硫化為硫代鉬酸根，而WO42-幾乎不被硫化。硫化過程中P2S5水解還將產(chǎn)生PO43-，在鎢冶煉過程中可用現(xiàn)有技術(shù)除去。因此，在鎢鉬分離工藝中，P2S5有望成為一種新型高效的鉬硫化劑。
關(guān)鍵字: 鎢；鉬；鉬硫化劑；五硫化二磷；分離；水解平衡；硫化；熱力學(xué)
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Hunan Key Laboratory for Metallurgy and Material Processing of Rare Metals,
Central South University, Changsha 410083, China）
Abstract:Currently, molybdenum is removed from tungstate solution by taking the advantage of different affinity towards S between W and Mo. Aiming at the problem of low sulfur content and high price of Mo sulfiding agent existing in tungsten extractive industry, we try to utilize the phosphorus pentasulfide as a new sulfiding agent and wish the generated HS- in the hydrolysis of P2S5 to provide the needed sulfur for Mo-sulfidation. Thus, the hydrolysis equilibrium of P2S5 in aqueous solution and thermodynamic behaviour of W amd Mo sulfidation were studied detail. The results show that the generated HS- in the hydrolysis of P2S5 can provide HS- for Mo-sulfidation. And, when n(S)/n(Mo) is 8 and the solution pH value is 7-9, MoO42- can be completely sulfurized to MoS42-, while tungsten still exists as WO42-. In addition, although the impurity PO43- is generated in the hydrolysis of P2S5, it can be removed easily and economically through the current technology in tungsten extractive industry. Therefore, P2S5 is expected to be a new efficient Mo sulfiding agent in the separation process of W and Mo.
Key words: tungsten; molybdenum; Mo-sulfidation agent; phosphorus pentasulfide; separation; hydrolysis equilibrium; sulfidation; thermodynamics
