脆硫铅锑精矿富氧直接熔炼基础研究

The jamesonite ore existing in our country is a kind of complex polymetallic sulfide ores of high value in use. At present, its production process consists of boiling roasting- sintering- blast furnace reduction smelting - reverberatory furnace blowing- reverberatory furnace reduction smelting. The low level of equipment and technology lead to low metal recovery, high energy consumption and serious environmental pollution problems. Herein we propose a new oxygen-enriched direct smelting process of Jamesonite concentrates, which has merits of short flowsheet, energy saving and being environmental-friendly, etc. The main subjects in this study are list as followed: studying the decomposition behavior of the main metal compounds in raw material at different temperatures; calculating the relationship between Gibbs free energy of core reactions and the temperature in smelting process; Building the thermodynamic system of oxygen-enriched direct smelting by drawing the logPO2-logPS2 predominance diagrams of Pb-Sb-S-O system; investigating the transition rules of sulfides, oxides and the metal, and revealing the reaction mechanism of the smelting process; determining reasonable slag phase composition by the combination of calculated software results and experimental data; studying the distribution discipline and influencing factors of valuable elements in alloy-slag phase so as to establish process optimization and control mechanism. This study is aimed to establish a technical model and provide with theoretical guidance for oxygen-enriched direct smelting of Jamesonite concentrates, which can also be applied to other Pb-Sb complex sulfide ores.

我国脆硫铅锑矿为复杂多金属硫化矿，具有极高的资源利用价值。目前其生产工艺为沸腾焙烧-烧结=鼓风炉还原熔炼-反射炉吹炼-反射炉还原熔炼，装备和技术水平的落后导致金属回收率低、能耗高、环境污染严重等问题。我们提出脆硫铅锑精矿富氧直接熔炼新工艺，具有流程短、绿色环保、高效节能等优点。本课题主要研究：原料中主要金属化合物在高温下的热分解行为；计算熔炼过程主要反应的吉布斯自由能随温度的变化关系，绘制不同温度Pb-Sb-S-O系logPO2-logPS2优势区图，构建富氧直接熔炼热力学体系；研究熔炼过程硫化物、氧化物、金属间的转变规律，揭示熔炼过程反应机理；通过热力学软件计算并结合实验研究，确定合理渣相组成；研究有价元素在合金-渣相间的分配规律及其影响因素，建立过程优化与调控机制。为脆硫铅锑精矿富氧直接熔炼提供技术原型和理论指导，也为其它铅锑复合硫化矿的富氧直接熔炼提供理论指导。

开展脆硫铅锑精矿富氧强化熔炼直接提取铅锑合金新工艺研究，对提高我国复杂铅锑矿冶炼技术水平和锑工业可持续发展意义重大。本项目以广西脆硫铅锑精矿为对象，以富氧直接熔炼提取铅锑合金为目标，主要完成如下工作：（1）查明了脆硫铅锑精矿及其热分解产物中铅、锑的物相组成与赋存状态；（2）建立了脆硫铅锑精矿富氧直接熔炼一步得到铅锑合金的热力学基础，明确了复杂铅锑硫化矿直接熔炼获得铅锑合金的热力学条件；（3）揭示了脆硫铅锑精矿富氧直接熔炼过程反应机理和锑、铁进入合金的内在原因；（4）确定了脆硫铅锑精矿富氧直接熔炼合理渣相组成；（5）查明了脆硫铅锑精矿富氧直接熔炼过程优化与调控机制。. 在氧化熔炼温度1250℃，富氧浓度60%vol，反应时间60min，Fe/SiO2 1.1，CaO/SiO2 0.9条件下，脆硫铅锑精矿富氧直接熔炼铅锑合金品位> 97%、合金直收率>80%、渣含金属（Pb+Sb）<1%，氧化熔炼炉渣无需还原熔炼即可直接烟化，真正实现脆硫铅锑精矿富氧直接熔炼一步获得铅锑合金。. 本研究突破传统锑冶炼方法，创新性提出富氧强化熔炼技术一步提取铅锑合金，构建铅锑复杂矿富氧直接熔炼的热力学体系，揭示脆硫铅锑精矿中铅、锑及其伴生有价元素在熔炼过程中的行为及其调控机制，不仅为脆硫铅锑精矿富氧直接熔炼新工艺提供技术原型和理论指导，也可为其它铅锑复合矿的富氧直接熔炼提供理论指导。