X射线荧光光谱法测定铁矿石的化学成分

应用X射线荧光光谱法测定铁矿石中铁等多种元素时,采用了熔融片制样,以消除矿物结构效应,降低基体效应的影响。并研究了熔样的条件,确定了仪器最佳参数,然后建立工作曲线。实验证明,本法快速、准确,能很好地对铁矿石进行测定,不仅大大缩短了分析时间,提高了工作效率,而且降低了劳动强度。     

唐山地区铁尾矿综合利用及产业化研究

对唐山地区铁尾矿组成成分和分布特征进行了分析,该地区铁尾矿属高硅型尾矿,其总堆存量非常大,约有4.58亿m3。在此基础上,研究了唐山地区铁尾矿的综合利用的途径。基于充分发挥尾矿资源效益、经济效益和环境效益的原则,提出了铁尾矿整体综合利用方案。针对唐山地区铁尾矿综合利用形成产业化存在问题,通过分析,认为提高矿山企业综合利用尾矿资源的意识、建立尾矿动态信息系统、加强尾矿利用的科研开发力度是实现唐山地区铁尾矿利用产业化的根本途径。     

我国铁尾矿综合利用现状和存在的问题

近年来铁精矿的市场价格不断攀升,一些低品位矿石有了开采价值,致使我国铁尾矿堆存数量不断增加,不仅占用土地资源,还造成严重的环境污染.综合利用这些铁尾矿资源,创造经济效益的同时减少环境污染显得日益重要.对目前我国铁尾矿的综合利用现状进行了综述,指出当前我国尾矿综合利用存在的一些问题并提出建议.     

世界铁矿石需求,供给及对我国进口铁矿石的建议

世界铁矿需求量今后十年将会增加,国际市场上高品位富矿块和球团矿则将出现短缺。但如果各铁矿石出口国争上项目扩大产能,也有可能出现80年代中期矿石过剩价格下跌的局面。我国发展钢铁工业应立足于优先开发国内资源。经济比较表明,内地的钢铁企业用国产矿有利,沿海的钢铁企业用国产矿不利,用进口矿反而有利。进口铁矿石既可采取长期合同方式买矿,也可择优合资经营到国外开矿。今后除由巴西、澳大利亚、印度、南非、秘鲁等国进口外,还应研究从越南、蒙古、东南亚、非洲、俄罗斯进口铁矿石。建议改革行业管理体制,实行煤铁联营。若每年少出口500万t精煤,少进口645万t铁矿石,可用产能500万t精煤的投资开发产能1645万t国产铁矿,以顶645万t进口矿。这样,不但减轻了铁路运煤和港口装卸的压力,而且国民经济效益显著,由于“煤铁联营”所获经济效益应划归煤炭部门。     

姑山铁矿露天转地下开采境界顶柱合理厚度研究

以姑山铁矿为工程背景, 针对采用进路充填采矿法的露天转地下开采矿山, 提出将露天转地下开采留设的境界顶柱简化为“梯度荷载作用下的悬臂梁超静定”平面应变力学模型, 采用弹性力学半逆解法求解出境界顶柱各应力分量的解析解, 并以抗拉强度为破坏指标, 计算出境界顶柱合理厚度的理论值。运用此方法计算出姑山铁矿露天转地下开采境界顶柱合理厚度的理论值, 并以此为基础数据, 结合FLAC^3D数值模拟获得了该矿境界顶柱合理厚度范围为23～25 m。     

Antimony Mobilization through Two Contrasting Gold Ore Processing Systems,New Zealand

Antimony, a toxic metalloid similar to arsenic, is present at variable levels in most gold-bearing rocks. Antimony is soluble in the surface environment, so antimony (Sb) mobilization in mine waters is an environmental issue around gold mines. The Reefton gold mine was originally developed in gold-bearing quartz veins; Sb concentrations were low (<100 mg/kg) compared to arsenic (As) concentrations (>1,000 mg/kg), and the mine waters had low dissolved Sb (<0.1 mg/L). A second stage of gold mineralization at Reefton involved brecciation and cataclasis of quartz veins and wall rocks, with addition of stibnite (Sb₂S₃). Processing of this ore has resulted in higher dissolved Sb in mine waters (0.1–1 mg/L), even after water treatment that removes most dissolved As (to 0.01 mg/L) by adsorption to suspended iron oxyhydroxide. Competition between As and Sb for adsorption sites on iron oxyhydroxide particles may have resulted in partial exclusion of the more weakly adsorbed Sb. The high rainfall (2,000 mm/year) at Reefton ensures adequate dilution of mine waters after discharge. The Macraes gold mine has no stibnite, and most Sb is in solid solution in the abundant arsenopyrite (Sb up to 2,000 mg/kg). Pit waters have both Sb and As dissolved up to 0.1 mg/L, partly because of evaporative concentration in a low-rainfall environment. Macraes tailings waters have high As (up to 3 mg/L) but negligible Sb (<0.001 mg/L). Reefton mine gold-bearing concentrate, containing stibnite, is transported 700 km to be processed by autoclave oxidation and cyanidation at the Macraes mine. This introduction of additional Sb to the Macraes site substantially increases the Sb content of the process stream periodically. Tailings from this process have up to 3 wt% Sb, dispersed through As-rich iron oxyhydroxides that are formed in the autoclave. The Sb-rich tailings are strongly diluted (approximately 100:1) by the Macraes tailings, and adsorption of Sb to iron oxyhydroxides in the tailings piles ensures that there has been no increase in the Sb content of the tailings water since the Reefton concentrate has been added at Macraes.     

拜耳法赤泥选铁工艺研究

以拜耳法赤泥为原料,在分析赤泥性质的基础上,考察赤泥选铁的途径和最佳条件。分析发现赤泥铁渣中主要矿物为赤铁矿和水化铝硅酸盐。研究了以磁化焙烧-磁选工艺从赤泥中回收铁精矿的工艺技术,并确定赤泥选铁的最佳工艺参数为焙烧温度750 ℃,焙烧时间20 min,掺碳量6%,磁选次数2次,磁选磁感应强度0.1 T。此工艺条件下得到的铁精矿品位为62.36%,回收率49.60%,S含量0.273%,达到了试验效果。     

Options for the Swedish steel industry - Energy efficiency measures and fuel conversion

The processes of iron and steel making are energy intensive and consume large quantities of electricity and fossil fuels. In order to meet future climate targets and energy prices, the iron and steel industry has to improve its energy and resource efficiency. For the iron and steel industry to utilize its energy resources more efficiently and at the same time reduce its CO₂ emissions a number of options are available. In this paper, opportunities for both integrated and scrap-based steel plants are presented and some of the options are electricity production, fuel conversion, methane reforming of coke oven gas and partnership in industrial symbiosis. The options are evaluated from a system perspective and more specific measures are reported for two Swedish case companies: SSAB Strip Products and Sandvik AB. The survey shows that both case companies have great potentials to reduce their CO₂ emissions.     

Electrochemical and chemical enrichment methods of a sodic–saline inoculum for microbial fuel cells

In microbial fuel cells (MFCs) efficient extracellular electron transfer microbes, also known as anode-respiring bacteria, play an important role on cell performance. This type of microbes can be developed by application of enrichment procedures. The objective of this study was to compare a chemical (only C, final terminal electron acceptor Fe(III)), an electrochemical (only E), and a hybrid method (H, i.e., E followed by 3 serial transfers in iron (III) citrate medium) enrichment methods departing from a saline–sodic soil inoculum. In the electrochemical enrichment procedure in an electrolysis cell, the inoculum was subjected to a continuous electrical stress continually by posing the cell at −150 mV/SCE (+94 mV/SHE). The only C enrichment method delivered powers superior to the only E one (higher values of P_An,max = 49 mW m⁻² and P_V,max = 558 mW m⁻³ of C compared to 33 and 379 of only E). Interestingly, overall resistance as determined by EIS was lower for only E (1240 Ω) than for only C (1632 Ω). Yet, the hybrid H method, showed electrochemical characteristics consistently superior to both only C and only E methods (higher P_An,max and P_V,max, lower internal resistance). Further detailed electrochemical studies of only E-method showed that the anodic resistance decreased with the time of operation of the electrolysis cell that would be consistent with the adaptability/enrichment purpose of the method. Also, Cyclic voltammetry peaks with values close to those reported for bacterial cytochromes appeared with time of cell operation.     

大功率氧煤燃烧器内冷态流场试验研究

研究热风管中不同结构的氧煤枪出口下游冷态两相流场。提出高炉炼铁大功率氧煤燃烧器新型结构。用流场显示，热球风速仪，三孔探针和取样探针给出其中时均速度场、回流区大小、位置及颗粒浓度分布。冷态试验结果表明：大口径同轴射流渐扩式大功率氧煤燃烧器在加强氧煤混合，增长煤粉停留时间，强化枪体冷却。延长使用寿命上会有好的效果。为实现提高大喷煤量气化率的热态试验和结构优选提供了依据。