难浸金矿生物堆浸存在问题与对策

综述了难浸金矿生物堆浸的历史及现状,比较了国内外在该技术领域的差距,分析了其中存在的问题。认为我国通过近20 年的开发研究,目前仍处于室内与现场交替试验时期。通过室内试验和现场实践,从矿石性质角度分析认为酸耗量、渗透性差、硫含量低和金矿物受机械包裹的难浸矿石在目前条件下仍难以用生物堆浸的手段予以处理。另外,还从试验周期、室内外试验结果的差异、自然条件和氧化菌种等方面探讨了生物堆浸技术发展所需的环境和条件,提出了相应的对策。最后,通过对我国现有的资源优势、目前的市场条件、近年来我国在该技术领域的开发经验及该技术延伸领域(难浸金精粉的堆式生物氧化、难浸金矿的堆式生物氧化+ 炭浸提金) 应用探讨,认为生物堆浸技术在难浸金矿资源的开发利用领域有着广阔的应用前景。     

难浸金矿氰化提金的现状与问题

难浸金矿是今后黄金工业发展主要依托的资源。近10多年来,对难浸金矿的预处理和随后的氰化提金进行了大量的研究与开发工作,其中氧化焙烧、湿法加压氧化和微生物氧化的三种预处理方法已得到了工业应用。简要评述了难浸金矿氰化提金的现状与问题。     

耐温菌氧化浸出预处理难浸金矿及其工业实践

综述了耐温菌生物氧化浸出难浸金矿的研究和发展概况,并介绍了西澳中等耐温菌预浸含砷金精矿生产厂的技术经济指标、生物氧化反应器的设计和参数,以及各工艺间的综合协调和生产概况。     

难浸金矿预处理技术及其应用

综述了一些比较典型的难浸金矿的预处理技术及其工艺方法,预处理方法主要有焙烧法预处理、生物氧化预处理、富氧或加助浸剂预处理、碱浸预处理、微波加热预处理等。难处理金矿将成为我国黄金工业发展的主要资源,因此难浸金矿的处理及预处理技术的开发与研究是当前我国黄金工业提金的关键。     

小曲碌沟金矿矿石微生物预氧化试验研究

小曲碌沟含砷、锑难浸金矿石经生物经后全泥氰化金的浸出率由原来的54．30％提高到92．15％；－15mm粒级试样经54d生物氧化后，氰化浸金，金的浸出率由未氧化的39．60％提高到70．88％。     

含砷锑硫难处理金矿预处理技术研究进展

含砷锑硫难处理金矿由于金的包裹、共生及提取过程二次包裹等原因,导致其常规提取工艺金回收率低,而预处理技术对金回收率的提高具有至关重要的作用。分析了含砷锑硫难处理金矿难浸的原因,总结了焙烧法、加压氧化法、生物氧化法等含砷锑硫难处理金矿预处理技术的研究进展,分析了各工艺技术的优缺点,并对各工艺的选择应用提出了建议。     

从顽金矿中浸金综述

本文主要对现有的顽金矿预处理方法进行综述。当金以细微颗粒弥散于硫化物、砷硫化物、碲化物、碳质或粘土矿物中时,直接碱式氰化对金的提取是无效的。然而通过预处理方法可以从难处理矿物中释放出金,预处理方法有:热氧化法如焙烧法;化学氧化法如酸浸、加压酸浸式或加压碱浸法;生物氧化法如用氧化铁杆菌的生物浸出法。随后通过碱式氰化从氧化物质中回收金。除了各种预处理方法之外,用硫脲或炭浸法从碳质金矿或金精矿中直接回收金也是可行的。     

难浸金矿预处理技术及其研究进展

随着易浸金矿的不断减少,难浸金矿应用比重越来越大,总结难浸金矿的预处理技术及其研究进展有重要意义。简要分析了难处理金矿难浸的原因,指出难浸金矿在浸出前进行预处理的必要性,对加压氧化法、焙烧法、生物预氧化法和超细磨法等难浸金矿的预处理方法以及新的预处理技术进展进行了总结,评述了各预处理方法的优缺点,在此基础上,对难处理金矿的预处理技术研究前景进行了展望。     

含锑难处理金矿臭氧氧化预处理工艺研究

为解决含锑金精矿难处理的问题,对某含锑金矿进行臭氧氧化浸出锑的实验研究。实验结果表明,氧化浸出优化工艺参数：温度75 ℃,HCl浓度4.5 mol/L,浸出时间4 h,液固比10∶1,臭氧浓度121.9 g/L。在此条件下,锑的浸出率为98.13%,硫的浸出率为43.52%。经过臭氧氧化浸出处理后,矿物中的金得以在渣中富集。对原矿和浸锑渣进行硫脲浸金试验,金浸出率分别为12.36%和70.17%,表明预处理取得一定效果,实现了含锑难处理金矿中锑和金的综合回收。研究结果能为臭氧氧化浸出辉锑矿和含锑难处理金矿预处理提供理论指导。     

难浸金精粉箱式静态生物氧化试验研究

介绍了难浸金精粉箱式静态生物氧化的基本方法流程,试验样品采用该方法处理187d 后,金的浸出率由37.04 %提高到93.01 % ,基本达到槽式搅拌氧化93. 68 %的水平。经济分析认为小型金矿山采用箱式静态生物氧化处理难浸金精粉,投资、成本分别为槽式氧化的1P3 和1P2 ,具有很强的实用性。     

烧结机头电除尘灰的分级利用

摘要：以某钢铁企业烧结机头电除尘灰为原料，采用水浸-过滤-蒸发浓缩-冷却结晶工艺研究KCl的回收试验及浸出渣的再利用。研究浸出时间、液固比、搅拌速度和浸出温度等因素对KCl的回收效果的影响。结果表明：1号、2号电场除尘灰经过一次水洗浸出后，碱金属K、Na的脱除率分别达99.90%、99.99%和99.85%、99.93%，浸出渣铁品位为47.51%和43.90%，重金属Pb质量分数为0.14%和0.57%，浸出渣可返回烧结工序；3号、4号电场除尘灰经过二次水洗浸出后，碱金属K、Na的脱除率分别达99.34%、99.66%和99.38%、99.69%,浸出渣铁品位为35.19%和20.86%，重金属Pb质量分数为10.86%和14.50%，浸出渣可作为火法回收铅的原料。浸出液经过蒸发浓缩冷却结晶，得到产品中KCl质量分数为93.39%。     

Al,Mo,B,Zr对GMR235合金组织和性能的影响

为了研究微量元素对合金组织和性能的影响,在GMR235合金基础上对合金成分进行调整,合金采用真空冶炼,其中1#～5#试样铝含量(%,质量分数)不同,设计成分分别为Al:3.0%,3.3%,3.6%,3.9%和4.3%;6#～10#试样的含钼量不同,设计成分分别为:4.5%,4.8%,5.1%,5.6%和6.0%;11#为中间成分未添加Zr,12#试样为中间成分添加了B,Zr;13#～17#试样的含硼量不同,设计成分分别为:0.025%,0.040%,0.050%,0.060%和0.070%;首先,以观察不同的Al,Mo,B,Zr含量对力学性能的影响。用热力学计算分析GMR235合金可能析出的平衡相、用扫描电镜进行组织观察,对试样进行650℃拉伸试验、816℃/345 MPa持久试验。结果表明,适量的加入Al,Mo,B元素可提高合金的力学性能,Al含量3.65%～3.73%范围内、Mo含量4.92%左右、B含量0.038%左右的综合性能最好。合金元素B,Zr的添加可明显改善合金的持久寿命和塑性,抑制碳化物的析出,使碳化物颗粒细化。     

铀矿渣拌酸熟化酸度对比试验

以微生物柱浸试验的卸柱矿渣为原料,使用100、150、200g/L的酸液进行拌酸熟化,熟化装柱后实行5%～10%日喷淋量20h的喷淋制度。结果表明,喷淋38天后,铀累计浸出率分别为22.2%、28.1%、33.8%,渣计浸出率分别为29.55%、32.96%、40.03%,耗酸率分别为0.23%、0.62%、0.85%。从经济角度出发,建议采用200g/L的酸度进行拌酸熟化比较适合。     

微波灼烧-X射线荧光光谱法测定还原铁中5种成分

介绍了微波快速灼烧技术在X射线荧光光谱法分析还原铁中5种成分的应用。实验表明:采用微波灼烧技术对还原铁样品进行预氧化,还原铁样品烧损值近－30%时,相对标准偏差小于0.15%; 采用X射线荧光光谱法对微波灼烧后的还原铁样品进行测定,当TFe、SiO₂、CaO、P₂O₅、Al₂O₃含量分别为89.96%、2.29%、0.11%、0.16%、0.78%时,其相对标准偏差分别为0.20%、4.1%、1.6%、1.4%、5.0%;还原铁样品的TFe含量在80％以上时,其测定结果的允许差在±0.5%以内,其它成分的X射线荧光光谱法分析结果与化学湿法分析结果也相符。     

Degradation of Extraction from Seaweed and Its Complex with Rare Earths for Organophosphorous Pesticides

On the basis of several experiments carried out in China, it was proved that both seaweed liquid fertilizer and rare earth （RE） could promote the growth of crops and increase their yield. The effects of extraction from seaweed and its complex with RE on the degradation of organophosphorous pesticides and the yield of vegetables were investigated. The resuits showed that the extract and its complex with RE could degrade organophosphorous pesticides in neutral solvent. The residues of the pesticides treated by the extract decreased by 96.88 %, 52.30%, 49.52%, and 22.88 %, respectively, for chlorpyrifos, dichlorvos, omethoate, and dimethoate, and those by the complex decreased by 95.99%, 54.23%, 48.79%, and 25.66%, respectively, when compared with the control. The residues of chlorpyrifos and dimethoate in spinach sprayed with the complex were decreased by 90.64% and 76.56%, respectively, compared with those in spinach from control plots when the interval between spraying and sampling was 8 d. The fresh weight of brassica chinensis and cabbage increased by 28.62% and 18.72%, and their dry weight increased by 44.49% and 14.74%, respectively, compared with those of the controls. The chlorpyrifos and dimethoate residues in brasscia chinese were decreased by 36.36% and 50.00%, respectively, and their rate of decrease in cabbage was 40.00% and 75.00%, respectively, on 5th day after spraying with the complex, when compared with those in the vegetable from control. These results suggest that this complex can increase the agricultural productivity and reduce the use of pesticide residues in the production of vegetables.     

高纯亚硝酸钠中杂质测定

分析评价高纯亚硝酸盐中杂质含量是亚硝酸根检测及相关标准物质量值溯源的基础。以高纯NaNO₂为例,采用离子色谱法测定阴离子杂质含量,定性分析主要阴离子杂质为Cl^-、NO^-₃和SO^2-₄;采用电感耦合等离子体原子发射光谱法(ICP-AES)测定K、Ca、Mg含量;采用电感耦合等离子体质谱法(ICP-MS)测定其他阳离子杂质含量(K、Ca、Mg除外),发现其他主要阳离子杂质为B和Sr。结果表明所测杂质在线性范围内,线性相关系数均大于0.9990;Cl^-的检出限为0.001%(质量分数,下同),NO^-₃和SO^2-₄的检出限为0.003%,K的检出限为0.004%,Mg的检出限为0.0009%,Ca的检出限为0.00003%,B的检出限为0.000015%,Sr的检出限为0.0000074%。按照实验方法测定高纯NaNO₂中Cl^-、NO^-₃、SO^2-₄、K、Ca、Mg、B和Sr含量,测定结果的相对标准偏差(RSD,n=10)为1.8%~3.5%,加标回收率为96%~104%。方法用于高纯NaNO₂中杂质含量测定,得到Cl^-、SO^2-₄、NO^-₃、K、Mg、Ca、B和Sr的含量(质量分数,下同)分别为0.0054%、0.037%、0.033%、0.02%、0.0063%、0.0035%、0.00226%和0.000268%。实验方法可为亚硝酸根及亚硝酸盐相关测定及标准物质研制提供技术支持,研制的相关标准物质可保证亚硝酸根的量值溯源。     

由矿物原料直接制备锰锌软磁铁氧体的研究

以软锰矿、硫化锌精矿及铁屑等为原料,研究了直接法制备锰锌软磁铁氧体的工艺条件,重点研究了浸出液复盐沉淀深度净化的工艺条件。同时浸出和初步除杂过程中,Fe,Mn和Zn的浸出率分别为91．3%,98．2%和81．4%；Cu~(2 ),pb~(2 ),Cd~(2 ),Ca~(2 )和Mg~(2 )的去除率分别为96．23%,91．63%,88．45%,94．63%和90．93%。沉淀剂硫酸铵的浓度和溶液酸度是复盐沉淀深度净化深度除Si的主要影响因素,其优化条件为：浸出液pH=1．5～2．5,游离硫酸铵浓度2．0～2．5 mol/L,时间1．0～1．5 h,室温。共沉淀粉料中各杂质元素的质量分数很低,其平均值为Ca 0．0069%,Mg 0．0165%,SiO_2 0．014%,Pb 0．00112%,Cu 0．00268%,Cd 0．00209%。各样环磁性能指标接近日本TDK公司PC30产品标准。     

Possible uses of positron emission tomography in breast carcinoma

The aetiology, biochemistry, clinical features and complications of histologically confirmed hepatic cirrhosis in 45 patients (26 females, 19 males) seen at the University Hospital of the West Indies, Jamaica, between 1984 and 1994 are presented. The age range was 1 to 72 years (mean 48 years). Abdominal swelling and weight loss were the commonest symptoms, occurring in 51% and 47% of patients, respectively. Jaundice was a presenting feature in 44%. Hepatomegaly was present in 71% of patients and splenomegaly in 33%. The aetiological factors were: alcohol (36%), bush tea (18%), chronic active hepatitis (11%), drugs (7%), and haemochromatosis (2%). Hepatitis B surface antigen was detected in 2 of 20 patients tested. 24% of the patients also had diabetes mellitus., 29% were anaemic, 29% were thrombocytopenic, 4% were leukopenic, and the prothrombin time was prolonged in 22%. The albumin/globulin ratio was reversed in 71% of the patients. The alkaline phosphatase was elevated in 56%, the aspartate aminotransferase was increased in 58% and the gamma glutamyl transpeptidase in 56%. 56% of the patients had macronodular cirrhosis; the liver showed a micronodular pattern in 18%; 7% had biliary cirrhosis; 7% chronic active hepatitis with cirrhosis; and 13% showed a mixed macro-micronodular pattern. Ascites and fluid overload developed in 44% of the patients. Hepatic encephalopathy occurred in 18% and upper gastrointestinal bleeding in 18%.     

Relationship between hamstring strains and leg muscle strength. A follow-up study of collegiate track and field athletes

Between August 1988 and October 1992, 1,052 patients underwent 1,522 valve procedures in our institution. Their mean age was 32.69 years (range 1-90). The etiology was rheumatic in 724 (68.8%), congenital in 120 (11.4%), degenerative in 99 (9.4%), infective in 58 (5.5%) and ischemic in 17 (1.6%). The mean preoperative functional class (NYHA) was 2.95 and 780 (74.1%) were in sinus rhythm. Repair was possible in 885 (58.1%) valves. The rate of repair versus replacement was 94.5% for the tricuspid, 56.2% for the mitral and 43.6% for the aortic valve. The total hospital mortality was 4.18%. For isolated mitral surgery it was 2.94%, for isolated aortic 4.12% and for isolated tricuspid 15%. Double valve surgery carried a mortality of 3% and triple valve surgery 13%. Hospital mortality for isolated mitral and isolated aortic surgery was lower for repair than for replacement (1.5% vs. 5% and 0 vs. 6.8%). The follow-up was 94.65% complete. The total incidence of embolic events was 2.93% with an actuarial freedom at 48 months of 92.71 +/- 5.35% for repair, 88.22 +/- 6.26% for replacement and 90.31 +/- 5.65% for patients with repair and replacement. Late mortality was 4.5%. The actuarial survival excluding hospital deaths was 94.89 +/- 2.10% for repair, 86.84 +/- 2.84% for replacement and 91.33 +/- 2.73% for the mixed group. The reoperation rate was higher for repair (13%) than for replacement (0.1%). This rate was highest for the rheumatic mitral patients with an age below 20 years (25.2%).(ABSTRACT TRUNCATED AT 250 WORDS)     

从含稀有金属炉渣中富集稀有金属的研究

采用不同条件浸出某含稀有金属炉渣,考察浸出条件对炉渣中氧化铝、氧化硅、氧化钙浸出率的影响。结果表明,采用稀酸浸出可以将稀土、铌、钛的品位分别提高到8.62%、5.40%、25.06%;采用"碳酸钠焙烧—水浸—酸浸"可以使稀土、铌、钛的品位分别提高到15.40%、9.97%、33.86%,稀土、铌、钛的直收率分别达到94.11%、94.27%、80.52%。