Reaction process of monazite and bastnaesite mixed rare earth minerals calcined by CaO-NaCl-CaCl2

The decomposition reactions of monazite and bastnaesite mixed rare earth minerals calcined by CaO-NaCl-CaCl2 were studied by means of TG-DTA and XRD. The results show that the process of the minerals decomposed by CaO involves two steps. The first step occurs in the temperature range of 425-540 ℃, and the main reactions are bastnaesite decomposition, i.e. REOF reacts with CaO to produce RE2O3 and CaF2, and Ce2O3 is oxidized to CeO2. During this step, CaCO3 is formed at about 500 ℃. The second step takes place in the temperature range of 610-700 ℃, and the reactions are monazite decomposition into RE2O3, Ca5F（PO4）3 and Ca3（PO4）2 by CaO and CaF2. In this process, the decomposition ability is improved because CaO from CaCO3 decomposing has high chemical activity. In calcining process, the new formed Ca5F（PO4）3 restrains fluorine that can escape in form of gaseous compound. The decomposition ratio of the mixed rare earth minerals reaches 90.8% at 700 ℃.     

Improvement of wear resistance of AZ31 and AZ91HP by high current pulsed electron beam treatment

The surface modification of magnesium alloys （AZ31 and AZ91 HP） was studied by a high current pulsed electron beam（HCPEB）. The results show that the cross-sectional microhardness of treated samples increases not only in the heat affected zone（ HAZ）, but also beyond HAZ, reaching over 250μm. This is due to the action of quasi-static thermal stress and the shock thermal stress wave with materials, which result in its fast deformation on the surface layer and so increases microhardness. For the AZ91HP alloy, a nearly complete dissolution of the intermetallic phase Mg17Al12 is observed, and a super-saturated solid solution forms on the re-melted surface, which is due to the solute trapping effect during the fast solidification process. Measurements on sliding wear show that wear resistance is improved by approximately 5.6 and 2.4 times for the AZ31 and AZ91HP respectively, as compared with as-received samples.     

鞍山钢铁工业循环经济发展模式选择

从鞍山钢铁工业的实际情况出发,提出了建设混合型钢铁生态工业园的鞍山钢铁工业循环经济发展模式。从园区内企业分类、种群共生关系分析、行业网络耦合、生态产业链设计和企业生态位分析等方面对鞍山钢铁工业生态系统结构进行了设计。     

钢铁工业循环经济实践分析与发展途径

从循环经济理论研究的一般性问题出发，分析了钢铁工业循环经济的实践情况；阐述了钢铁工业循环经济发展的总体思路；设计了多条钢铁工业生态产业链；提出了铁素高效利用、水循环利用、能量梯级利用、固体废弃物资源化利用、信息集成利用的钢铁工业发展循环经济的实施途径。     

Fe-PGMs合金废电解液溶析结晶制备硫酸亚铁

以Fe-PGMs合金电解精炼产生的废电解液为原料,无水乙醇作为溶析剂,使用溶析结晶法从废电解液中将硫酸亚铁结晶析出。考察了溶析时间、乙醇与水溶液体积比、溶析温度、搅拌速度、陈化时间、无水乙醇滴加方式对硫酸亚铁结晶率的影响。结果表明,在溶析时间60 min、无水乙醇与水溶液体积比为1:1、溶析温度10 ℃、搅拌速度200 r/min、陈化时间60 min、乙醇滴加方式为逐滴加入时硫酸亚铁结晶率达到最大92.98%。此工艺避免了电解过程中废电解液对环境的污染,实现了电解Fe-PGMs合金中电解液及Fe-PGMs合金酸浸液的循环利用。     

鞍山矿业循环经济建设初探

阐述了矿业循环经济的基本内涵,指出了矿业循环经济的概念、实施原则和方式.介绍了鞍山矿业的基本情况,回顾鞍山发展矿业循环经济的基本做法及成效,分析了当前存在的问题,并对鞍山进一步发展矿业循环经济提出了对策和建议.     

浸入式侧吹气流在熔池中的穿透行为

利用摄像和量纲分析的方法研究了渣罐水模型中浸入式侧吹气体的最大穿透行为,从而为提高气液间的反应速率及氧枪的布局等问题提供参考.研究表明,当喷枪直径一定时,气体的最大穿透深度随气流动量通量的增加而增大,当动量通量相同时,液体的黏度越大,气体的最大穿透深度越小.气体无量纲穿透深度的经验数学表达式计算结果与实测气体穿透深度基本相符.     

稀土硅铁合金冶炼工艺及反应机理

综述了硅热法还原高炉渣、稀土富渣、稀土精矿及碳热法还原稀土氧化物、稀土富渣、氟碳铈精矿等生产稀土硅铁合金的工艺特点和技术进展.指出碳热还原法较硅热法具有能耗低、稀土收率高、无工业废渣等优点.分析了碳热还原法冶炼过程中的有关物理化学反应,碳热还原法工艺的关键是要强化稀土碳化物的生成.     

Influence of NaCl-CaCl2 on Decomposing REPO4 with CaO

The influence of NaCl-CaCl2 on thermal decomposition of REPO4（RE： Ce, La, Nd, Th） with CaO was studied. The heat decomposing process of REPO4 was tested with TG-DTA experiments. The results showed that the decomposition temperature of REPO4 with CaO was reduced because of adding NaCl-CaCl2 mixture （NaCl：CaCl2 = 1：1 ）. The influence of the addition of NaCl-CaCl2, roasting temperature and roasting time on decomposition ratio of REPO4 with CaO was studied. The results showed that the decomposition ratio of REPO4with CaO was 79% when the addition percentage of NaCl-CaCl2 was 10%, the roasting temperature was 750℃, and the roasting time was 1 h.     

以NaCl-CaCl2为助剂CaO分解氟碳铈矿的研究

现行分解氟碳铈矿过程中,氟以气相形式逸出,既浪费氟资源,又污染环境。为了寻求新的清洁冶金方法,文中采用DTA-TG和XRD热分析技术对CaO-NaCl-CaCl2焙烧标题矿物分解过程的化学反应进行了研究。用二次正交回归实验设计方法研究了氟碳铈矿分解率随四因素而变化的规律,得出了相应的回归方程,并得出的优化工艺条件：温度：700℃;CaO加入量：15%（质量百分数）;NaCl加入量10%（质量百分数）;焙烧时间：60 min,分解率为92.14%。通过分析讨论可知：由于CaO的加入,氟以CaF2固体的形式存在于焙烧产物中,抑制了气相氟的产生,本文采用的方法是一种清洁冶金工艺。