Na_2CO_3-NaCl-C-PbSO_4-CuO体系热力学分析及应用研究

对Na_2CO_3-NaCl-C-PbSO_4-CuO低温熔盐炼铅体系进行热力学分析,绘制了600~1 200K时体系中主要反应的ΔGθT—T图。结果表明,在600~1 200K范围内,PbSO_4可以被还原成金属Pb,硫能够固定在CuS中,钠盐可转变成Na_2CO_3形态存在,且在1 123K时,体系中的稳定物相以金属Pb、CuS和Na_2CO_3为主。提出了Na_2CO_3-NaCl-C-PbSO_4-CuO低温熔盐炼铅新工艺。在1 153K下,以废铅酸蓄电池胶泥为原料、Na_2CO_3-NaCl为熔剂、CuO为固硫剂、焦粉为还原剂,进行了验证试验。产出的粗铅品位98.10%,铅直收率93.27%,铅的总回收率99.25%,93.81%的硫以CuS形式被固定在渣中,过程无SO2气体产生,与热力学分析结果相符合。     

NaOH-C-PbSO_4-ZnO体系热力学分析及验证

对NaOH-C-PbS0_4-ZnO低温碱性炼铅体系进行热力学分析,计算了在600~1 200 K温度下体系中主要反应的标准吉布斯自由能变化值(△G_T~θ),并绘制相应的△G_T~θ-T图。结果表明,在温度低于1 200 K的还原气氛条件下,PbSO_4可以被还原成金属Pb,ZnO能够发生固硫反应生成ZnS,钠盐可转变成碳酸钠形态存在。该体系在不同温度下的热力学平衡试验结果表明,温度为1 123 K(850℃)时,体系中的稳定物相以金属铅、硫化锌和碳酸钠为主。试验结果与热力学分析相符合。     

再生铅低温碱性固硫熔炼的实验研究

针对我国传统再生铅生产工艺所存在的熔炼温度高、能耗大、铅和低浓度SO₂烟气污染严重等弊端,在对NaOH-C-PbSO₄-ZnO低温碱性炼铅体系进行理论分析的基础上,提出了一种再生铅的低温碱性固硫熔炼新工艺.以废铅酸蓄电池胶泥(以下简称胶泥)为实验原料,采用单因素实验法分别考察NaOH用量、熔炼温度、焦粉用量及固硫剂ZnO用量对金属铅直收率和ZnO固硫率的影响.获得优化实验条件如下:m(NaOH)/m(胶泥)=60%,熔炼温度为860℃,m(焦粉)/m(胶泥)=10%,m(ZnO)=m(理论量).在此优化条件下进行综合扩大实验,铅的直收率为99.09%,获得粗铅品位为98.86%,ZnO固硫率为93.37%.X射线衍射图谱分析可知,反应后原料中硫主要以ZnS的形式固定在渣中,NaOH绝大部分转变为Na2CO3,生产过程中无SO₂气体排放.      

PbSO4-ZnO-C体系在Na2CO3熔盐中的反应行为

考察了PbSO4-ZnO-C体系中各组分在Na2CO3熔盐中的反应行为,揭示了PbSO4固硫还原炼铅的反应机理。结果表明：在873~1 123 K的温度范围内,PbSO4首先和Na2CO3反应生成PbO和Na2SO4,PbO和Na2SO4再分别被还原成金属Pb和Na2S;温度大于1 123 K时,Na2S和ZnO反应生成ZnS和Na2O,Na2O再和CO2反应生成Na2CO3。Na2CO3在PbSO4-C-ZnO固硫还原熔炼体系中不仅是充当反应介质,改善反应体系的传热、传质和动量传递效果,同时也是主要反应物之一;ZnO在反应过程中不仅是固硫剂,同时也是Na2CO3熔盐的再生剂。     

Na_2CO_3-NaOH-NaNO_3体系低温碱性熔炼工艺从废弃电路板中综合回收有价金属

采用Na2CO3-NaOH-NaNO3熔盐体系回收废弃电路板中的有价金属,考察Na2CO3-NaOH质量比、熔炼温度、熔炼时间、碱料比等因素对有价金属转化率的影响。结果表明,较为适宜的熔盐体系组成和工艺条件为:Na2CO3-NaOH质量比5.3∶16、熔炼温度700℃、熔炼时间40min、碱料比5∶1,在此条件下,锡、锌、铝、铅的转化率分别为84.55%、100%、93.71%、73.72%,铜以CuO形态富集在渣中。     

Na_2CO_3-NaOH-NaNO_3体系低温碱性熔炼工艺从废弃电路板中综合回收有价金属

采用Na2CO3-NaOH-NaNO3熔盐体系回收废弃电路板中的有价金属,考察Na2CO3-NaOH质量比、熔炼温度、熔炼时间、碱料比等因素对有价金属转化率的影响。结果表明,较为适宜的熔盐体系组成和工艺条件为:Na2CO3-NaOH质量比5.3∶16、熔炼温度700℃、熔炼时间40min、碱料比5∶1,在此条件下,锡、锌、铝、铅的转化率分别为84.55%、100%、93.71%、73.72%,铜以CuO形态富集在渣中。     

辉钼矿非氧化焙烧工艺的热力学分析

通过热力学研究了几种非氧化焙烧工艺处理辉钼矿的可行性工艺路线。采用高温真空分解法直接处理辉钼矿得到金属钼粉,可以直接用于炼钢,适宜的分解条件为:温度为1 700~1 900 K以及真空度小于100 Pa;气体产物硫可在392~490 K进行液化回收。选用氧化钙作固硫剂,碳作还原剂还原辉钼矿,可以得到Mo、Mo2C和CaS混合物,适宜的反应温度应控制在1 200 K以上。选用碳酸钠固硫剂,碳作还原剂还原辉钼矿,产物为Mo、Mo2C和Na2S,通过水洗可以得到纯度较高的钼粉,适宜反应温度应控制在900~1 100 K。     

炼铜烟灰碱浸脱砷的热力学及动力学

基于热力学计算,绘制了常温(298K)条件下Me-S-H2O系(Me:Cu,Pb,Zn,As)Eh-pH图,并对pH=13～15时As2S3、CuS、Cu2S、PbS、ZnS热力学稳定区进行分析。结果表明,在碱浸体系中,砷与铜、铅、锌等有价金属的分离在热力学上是可行的。基于NaOH与(NaOH+Na2S)两种体系中砷的浸出行为研究,为提高铜烟灰碱浸脱砷效率,选择(NaOH+Na2S)浸出体系是适宜的。在该体系中,在303～363K范围内,铜烟灰中砷的浸出过程受内扩散控制,浸出动力学方程遵循未反应收缩核模型。     

复杂锑金精矿与铅精矿协同熔炼过程热力学研究

以锑金精矿与铅精矿为研究对象,采用热力学软件FactSage计算协同熔炼过程各金属硫化物反应趋势、Me-S-O系优势区图及物相平衡分配规律。热力学分析表明,控制适宜的氧分压和硫分压可实现协同熔炼过程处在Pb(l)+Sb(l)热力学稳定区域,协同熔炼过程Sb2O5与PbS发生交互反应生成金属Pb、Sb的趋势较大,有利于实现熔炼过程Sb的回收和Au的捕集。验证试验表明,在熔炼温度1 200 ℃、CaO/SiO2=0.40、Fe/SiO2=1.05、富氧浓度90%的条件下,锑金精矿与铅精矿协同熔炼过程可顺利进行,合金中Pb、Sb收率均大于88%,渣中Pb、Sb含量均小于1%,合金中Au含量达78 g/t。     

MoS_2-CaO-O_2系热力学分析及应用

通过热力学计算得出温度为800,900 K时,不同Mo S2,Ca O,O2初始物质量条件下对应Mo S2-Ca O-O2体系的热力学平衡,确定辉钼矿石灰焙烧的反应机制。热力学分析表明,800 K时体系初始摩尔量Mo S2∶Ca O=1∶3时,随着氧用量的增加Mo(VI)优先与石灰、氧气结合生成CaMoO_4,然后S(II)被氧化生成CaSO_4,体系氧化最终热力学平衡产物为CaSO_4,CaMoO_4;800 K时体系初始摩尔量Mo S2∶Ca O=1∶2时,随着氧用量的增加,约70%的Mo S2首先生成CaMoO_4,Ca S,然后Ca S氧化为CaSO_4,最终CaMoO_4作为固硫剂与残余的Mo S2反应生成Mo O3和CaSO_4,最终对应热力学平衡产物为CaSO_4,Mo O3。理论上证明可以实现辉钼矿选择性钙化焙烧;温度从800 K提高至900 K时,不影响全钙化焙烧过程;对于选择钙化焙烧高温不利于CaMoO_4固硫,而富氧益于固硫。验证试验采用100 g辉钼矿与55 g氧化钙混匀,在温度为800 K的马弗炉中焙烧2 h,焙砂钼、硫固定率分别为98.36%,91.44%,X射线衍射(XRD)分析表明钼硫分别以Mo O3,CaSO_4存在,与热力学分析结论一致。     

熔炼次数对M17返回料合金成分、组织和性能的影响

实验结果表明,M17铸造高温合金(%:0.16C、8.79Cr、5.79A1、4.93Ti、3.29Mo、15.20Co、0.78V、0.015B、0.073Zr、0.002S、0.001P、0.001 1O、0.001 0N)经25 kg真空感应炉返回重熔后,Si含量随重熔次数的增加而略有增加,合金中主要元素和其它杂质元素S、P、H的含量变化不大,而氧、氮略有增加;合金中初生碳化物由新合金中的草书体逐渐向返回合金块状转变,初生碳化物的遗传性堵塞合金凝固时的补缩通道,使返回料合金的疏松倾向增大,高温塑性下降较大。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.