氰化浸出体系中金的溶剂萃取

本文评述了金的碱性氰化溶液溶剂萃取研究与开发工作的最新进展。包括改性胺，季铵盐，磷氧化物及胍类萃取剂等。     

简讯

由中国黄金总公司、中国金属学会等主办的88国际黄金技术、设备、仪器展览会暨技术研讨会7月1日至5日在北京举行。来自澳大利亚、加拿大、美国、日本、欧洲和东道主中国等12个国家和地区的29家公司参加展出,展示了黄金勘探,开采、重选)炭浆法等领域的工艺设备和辅助设施。同时,还举行了一系列技术研讨会,介绍金的矿物勘探,地下开采、砂金船、重力分选等的应用和发展     

Recovery of gallium from phosphorus industry flue

The flue dust generated during electric furnace production of elemental phosphorus was investigated for the recovery of gallium. Then the flue dust was slurried with water and blended with concentrated sulfuric acid, followed by ageing. The gallium in the dust was thereby converted to soluble sulfate. The factors affecting the dust curing were investigated to understand the process chemistry of the pretreatment. The optimal curing conditions are determined as follows: the mass ratio of dust to water and acid is 1 : 1 : 1, ageing temperature and time are 200℃ and 2h, respectively. Almost all the gallium available to acid dissolution in the dust, about 90% gallium, can be extracted by leaching the cured dust at 80℃ for 1h.     

Biomagnification of perfluoroalkyl compounds in the bottlenose dolphin (Tursiops truncatus) food web

The environmental distribution and the biomagnification of a suite of perfluoroalkyl compounds (PFCs), including perfluorooctane sulfonate (PFOS) and C8 to C14 perfluorinated carboxylates (PFCAs), was investigated in the food web of the bottlenose dolphin (Tursiops truncatus). Surficial seawater and sediment samples, as well as zooplankton, fish, and bottlenose dolphin tissue samples, were collected at two U.S. locations: Sarasota Bay, FL and Charleston Harbor, SC. Wastewater treatment plant (WWTP) effluents were also collected from the Charleston area (n = 4). A solid-phase extraction was used for seawater and effluent samples and an ion-pairing method was used for sediment and biotic samples. PFCs were detected in seawater (range <1-12 ng/L), sediment (range <0.01-0.4 ng/g wet weight (ww)), and zooplankton (range 0.06-0.3 ng/g ww). The highest PFC concentrations were detected in WWTP effluents, whole fish, and dolphin plasma and tissue samples in which PFOS, C8 and C10-PFCAs predominated in most matrices. Contamination profiles varied with location suggesting different sources of PFC emissions. Biomagnification factors (BMFs) ranged from <1 to 156 at Sarasota Bay and <1 to 30 at Charleston. Trophic magnification factors (TMFs) for PFOS and C8-C11 PFCAs indicated biomagnification in this marine food web. The results indicate that using plasma and liver PFC concentrations as surrogate to whole body burden in a top marine predator overestimates the BMFs and TMFs.     

Chlorobenzenes, chlorinated pesticides, coplanar chlorobiphenyls and other organochlorine compounds in Greenland biota

This paper summarises the levels and composition of chlorobenzenes, chlorinated pesticides, coplanar polychlorinated biphenyls (PCBs) and the chlorinated compounds octachlorostyrene (OCS), hexachlorocyclobutadiene (HCBD) and pentachloro-anisole (PCA) in biota from the terrestrial, freshwater and marine environment of Greenland. The data were obtained during the second phase of the Arctic Monitoring and Assessment Programme (AMAP). Of the chlorobenzenes, hexachlorobenzene was the main constituent detected in almost all samples. The chlorobenzenes accumulate in the marine food web in a similar manner to the better-studied persistent organic pollutants, with maximum concentrations in beluga, minke whale and narwhal. However, concentrations in ringed seals and kittiwakes were lower than in marine fish, contradicting biomagnification. Of the organochlorine pesticides, the drin pesticides (aldrin, endrin, dieldrin) and heptachlor had increasing concentrations along the food chain, whilst biomagnification was less pronounced for endosulfan, methoxychlor and mirex. Endosulfan and methoxychlor are pesticides still in use and considered less persistent than other organochlorine pesticides. Their occurrence in Arctic biota is of particular concern, also given the high acute toxicity of endosulfan to fish. Chlorobenzene and pesticide concentrations tended to be lower in the Greenland samples than in the same animals from the Canadian Arctic, whilst their concentrations were similar to samples from Svalbard and Iceland. However, temporal trends might overlap the geographical differences. Coplanar chlorobiphenyls (CBs) were found in all samples analysed, with the maximum concentrations found in marine mammals such as beluga and narwhal. Biota from the terrestrial environment appeared to be less contaminated. The main contributor on a TEQ basis was CB126. OCS, HCBD and PCA were detected in biota from Greenland, although at very low concentrations. OCS seems to have the widest occurrence and the highest potential for biomagnification of the three compounds analysed.     

黄磷电炉电尘浆提取镓的预处理

根据在电炉还原炼磷过程中,磷灰石中的镓在电尘浆中高度富集,成为可供利用的镓资源,提出了一种提取镓的预处理技术:用浓硫酸熟化电尘,将其中的镓先转化成水溶性化合物,再从预处理物料中浸出镓.考察了预处理过程中电尘的化学和矿物学变化以及影响镓提取率的因素,并给出了适宜的预处理条件;在最佳质量比电尘:水:硫酸=1:1:1,200℃下熟化2 h.实验结果表明,在优化条件下将预处理的电尘在80℃浸出1 h,镓的浸出率可达90%以上.     

浮选技术的非选矿运用

介绍了浮选技术在选矿以外的多种领域中作为分离方法的应用。包括固液分离、城市和工业废水处理、固体废弃物资源化等。给出了废纸浆浮选脱墨和废塑料浮选分离的实例。     

基于距离判别分析法的采空区塌陷预测

依据某开采区的勘察资料,建立了采空区稳定性预测的距离判别模型,选取影响采空区的主要因素作为判别因子,以实测样本作为训练样本,建立相应的线性判别函数对待判样本进行分类。研究结果表明,距离判别分析模型是采空区预测的一种有效方法,可以在实际工程中应用。