高砷难处理金精矿焙烧-氰化浸出工艺研究

对甘肃某高砷高硫难处理金精矿进行了氧化焙烧预处理—氰化浸出试验研究,取得了砷、硫脱除率分别达92.63%、99.81%,金的浸出率达85.23%的较好技术指标,可为有效利用高砷微细浸染型金矿资源提供参考。     

Effects of grilling and roasting on the levels of polycyclic aromatic hydrocarbons in beef and pork

The concentrations of seven polycyclic aromatic hydrocarbons (PAHs) viz. chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, and indeno(1,2,3-c,d)pyrene in 150 samples of commercial meat products were determined. The PAHs were extracted with hexane, purified with Sep-Pak Florisil cartridges and determined by high-performance liquid chromatography using a fluorescence detector. Levels of PAHs were dependent on the method of cooking and type of heat source used. Relatively high levels of PAHs, 10.2 μg/kg on average, were found in charcoal-grilled pork samples. Average PAH levels in beef did not exceed 0.80 μg/kg. Charcoal grilling of pork samples resulted in extremely high levels of benzo(a)pyrene (3.0 μg/kg), while the average benzo(a)pyrene levels in charcoal-grilled beef samples were 0.15 μg/kg. These data can be used to estimate the dietary exposure of consumers to PAHs and to assess any potential risk associated with the ingestion of these foods.     

含钒石墨尾矿提钒技术研究

金溪石墨矿矿石中钒含量较高,研究表明矿石经石墨浮选后钒绝大部分都进入尾矿中,因此从尾矿中回收钒成为开发金溪石墨矿必须解决的问题。为此,根据矿石中钒的特点,在借鉴石煤提钒技术的基础上,对浮选试验获得的金溪石墨尾矿进行了提钒试验。试验结果表明：采用加酸焙烧-水浸-除钾铝-萃取-反萃取-氧化沉钒工艺,可使金溪石墨矿浮选尾矿中钒的浸出率、萃取率、反萃取率和沉淀率分别达到95.5%、87.6%、99.9%和99.0%,同时可获得对浮选尾矿产率分别为9.2%和23.2%的钾明矾和铵明矾;此外,浸出渣主要由硅酸盐组成,并具有较高的活性,可以作为水泥掺合料和生产建筑材料的原料。     

难处理金矿的球团包衣焙烧预氧化法研究

本文讨论了一种用于含硫砷碳难浸金矿的全新预处理方法—球团包衣焙烧氧化法。该过程的最大特点是在精矿和粘接剂形成的球团外侧覆盖一层由硫砷固定剂组成的包衣层。球团焙烧氧化产生的二氧化硫和三氧化二砷气体以硫酸钙和砷酸钙的形式被固定在包衣层中 ,没有二氧化硫和三氧化二砷扩散到大气 ,不需要烟气净化设施 ,不会产生环境污染。总结了反应的热力学数据。试验所得指标为 :硫固定率大于 99.98% ,砷固定率大于 99.99% ,焙砂产率 74 % (相对精矿 ) ,去衣金损失率 0 .6 3% ,焙砂金浸出率 91.71%～ 92 .84 % ,优于普通焙烧氧化法的 78.6 3%。     

多金属硫精矿添加硫酸钠对硫酸化焙烧的影响

在湿法冶金中,添加少量硫酸钠对多金属硫化精矿的硫酸化焙烧的影响是:焙砂增重,银铜酸浸率提高,焙砂中硫酸根含量增加,气相中三氧化硫/二氧化硫也有提高,而铁的酸浸率却降低。研究表明:硫酸钠对多金属硫化精矿硫酸化焙烧和浸出具有促进作用。     

阳极泥处理

综合评述了国内外多种阳极泥处理技术,以最有代表性的铜阳极泥处理为例,较详细地介绍了国内外的典型流程及其特点。探讨了与阳极泥处理的各单元操作(焙烧、浸铜,分金、分银等)有关的分离和提纯技术的原理。在总结铜阳极泥处理技术新进展的前提下,指出了铜阳极泥处理技术的研究方向。笔者认为,铜阳极泥处理技术在不断完善改进现有流程的基础上,已进入综合回收多种有价金属的新阶段。     

钼精矿焙烧气体参数对环保和资源的影响

绝大部分钼精矿须经焙烧脱硫，该过程的严重污染和浪费缘于不合理的气体参数和稀释放应；调控此参数以抑制释释效应、制定新政策、结合硫酸生产实现钼精矿集约化焙烧，将有效促进污染防治和综合利用。     

低品位磷矿的选矿方法

阐述了我国磷矿石床的分类,分析并总结了不同类型磷矿石的选矿方法。     

Optimization of roasting conditions as an useful approach for increasing antioxidant activity of carob powder

Antioxidant activity, gastrointestinal solubility of polyphenols and formation of different classes of Maillard reaction products (MRPs) that occurs during thermal processing of carob powder was investigated in relation to different roasting time-roasting temperature combinations applied. Principal component analysis (PCA) was used to group carob powders with the aim of proposing optimal roasting conditions for obtaining the one with the highest biological activity that can be expected after undergoing the simulation of gastrointestinal digestion. Results showed that antioxidant activity of carob powder can be significantly increased by roasting due to improved polyphenol solubility and formation of the early-stage MRPs. Fluorescent MRPs, HMF and furfural, known for their toxic properties, were the most abundant in samples roasted under more severe time/temperature conditions. Carob powder roasted at 130 °C for 30 min yielded the highest antioxidant activity and the lowest toxic MRP formation.