(中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083)
摘 要: 總結(jié)焦銻酸鈉傳統(tǒng)處理方法的優(yōu)缺點，計算并繪制不同溫度下Sb-H2O系φ-pH圖。結(jié)果表明：在高溫高壓下可以用氧氣將不同形式的Sb3+氧化為Sb5+，提出在3種不同體系中采用加壓氧化方式制備焦銻酸鈉的清潔生產(chǎn)工藝。首先，用氧氣加壓氧化硫代亞銻酸鈉得到焦銻酸鈉產(chǎn)品，銻的沉淀率達(dá)到99.80%，與空氣氧化法相比，加壓氧化法大幅度縮短了氧化時間。其次，在KOH體系加壓氧化溶解銻白，焦銻酸鉀溶液加入NaOH沉淀產(chǎn)出焦銻酸鈉產(chǎn)品，加壓氧化過程銻白完全溶解，產(chǎn)品中幾乎不含Sb3+。再次，在NaOH體系銻白直接加壓氧化產(chǎn)出焦銻酸鈉，但焦銻酸鈉產(chǎn)物中Sb3+含量仍在1.0%左右。最后，在NaOH體系銻白配合溶解，亞銻酸鈉溶液經(jīng)過加壓氧化產(chǎn)出合格焦銻酸鈉產(chǎn)品，銻的沉淀率達(dá)到97.70%。這兩個體系用氧氣加壓氧化代替?zhèn)鹘y(tǒng)的H2O2，降低了成本。加壓氧化法為焦銻酸鈉的清潔生產(chǎn)工藝發(fā)展提供了一種新的思路。
關(guān)鍵字: 銻；加壓氧化；浸出；沉淀
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:The advantages and disadvantages of the traditional treatment methods of sodium pyroantimonate were summarized, and the φ-pH diagram of the Sb-H2O system at different temperatures was calculated and drawn. The result shows that the φ-pH diagrams of Sb-H2O system at different temperatures indicate that Sb3+ can be oxidized into Sb5+ with oxygen gas at high temperature and high pressure. Therefore, a series of clean technologies for producing sodium pyroantimonate by pressure oxidation in three different solutions were proposed. Firstly, sodium thioantimonite is oxidized with oxygen gas at high pressure to get the sodium pyroantimonate product, the precipitation ratio of antimony can reach 99.80%. And the reaction time of pressure oxidation is greatly reduced compared to that by air oxidation method. Secondly, Sb2O3 is dissolved in KOH solution by pressure oxidation to obtain a KSb(OH)6 solution, then NaOH is added into to prepare sodium pyroantimonate. Sb2O3 is completely dissolved during the pressurized oxidation process, and the product contains almost no Sb3+. Thirdly, sodium pyroantimonate can be directly prepared from Sb2O3 by pressure oxidation in NaOH system, but the Sb3+ content in this product is still among 1.0%. At last, Sb2O3 is dissolved in NaOH solution to get NaSb(OH)4 solution, and then qualified sodium pyroantimonate can be prepared from NaSb(OH)4 solution by pressure oxidation. The precipitation ratio of antimony reaches 97.70%. The pressure oxidation with oxygen gas in these two systems is used instead of the conventional agent of hydrogen peroxide, which has low cost. The pressure oxidation method provides a new idea to the development of clean production process for producing sodium pyroantimonate.
Key words: antimony; pressure oxidation; leaching; precipitation
