墨西哥矿业公司圣路易斯波托西锌厂浸出流程的改进

墨西哥矿业公司圣路易斯波托西锌厂采用传统的焙烧-浸出-净化-电积工艺处理锌精矿生产锌，其浸出流程按照混合锌精矿含杂质Fe≤7％设计。本文介绍该厂湿法系统近年来所做的改进。     

科明科特累尔锌厂的浸出和净化

加拿大不列颠哥伦比亚省的科明科公司特累尔厂锌的浸出和溶液净化工艺包括：锌精矿的直接加压浸出、来自铅厂烟尘的浸出、焙砂的浸出和溶液的净化。这些工艺已经与科明科锌、铅操作系统的独特性质相匹配。最近的改进包括净化工艺和铁渣处理工艺的变化。1997年，在加压浸出车间安装了一套新的5室高压釜及其完备的辅助设备系统。本文介绍这些变化、现有流程和进一步的改进。     

科明科特累尔锌厂的浸出和净化

加拿大不列颠哥伦比亚省的科明科公司特累尔厂锌的浸出和溶液净化工艺包括:锌精矿的直接加压浸出、来自铅厂烟尘的浸出、焙砂的浸出和溶液的净化。这些工艺已经与科明科锌、铅操作系统的独特性质相匹配。最近的改进包括净化工艺和铁渣处理工艺的变化。1997年,在加压浸出车间安装了一套新的5室高压釜及其完备的辅助设备系统。本文介绍这些变化、现有流程和进一步的改进。     

锌精矿氧压浸出技术研究进展

传统湿法炼锌工艺存在烟气处理成本高、综合回收率低等问题,近年来,氧压浸出技术因其原料适应性强、锌回收率高、环境污染小等优点被应用于锌冶炼工业。介绍了锌精矿氧压浸出的生产工艺,论述了浸出过程反应的基本原理,以及离子催化、温度、酸度、分散剂等条件对浸出过程离子行为的影响与机理。讨论了锌精矿中伴生元素铁、镓、锗、铟、银等的浸出行为及在不同浸出条件下浸出行为的变化。     

采用加压浸出工艺优化传统湿法炼锌流程研究

用传统湿法炼锌厂的热酸浸出液在高压釜中浸出锌精矿。结果表明,在温度130℃,液固比14∶1,精矿粒度-50μm占96%,浸出时间3h,氧分压600kPa,添加木质素磺酸钙0.4%的条件下,锌浸出率达97%以上,浸出液中的铁含量低于2g/L,加压浸出液可直接返到传统湿法炼锌流程的中性浸出,同时精矿中的硫以元素硫形式进入渣相。该工艺流程易与传统湿法炼锌厂现有流程结合,具有同时浸锌除铁、工艺流程简单、对环境友好等优点。     

黄铜矿精矿的三氧化铁浸出

本工作对采自古巴的、粒度为－３１５＋２００μｍ的黄铜矿精矿（３２．３％Ｃｕ）的浸出动力学特性进行了研究。测定的表观活化能值为Ｅａ＝５５±５ｋＪ／ｍｏｌ，与已发表文献的结果一致。显微镜和Ｘ射线研究证实，通过测定实际结构变化，可以观察到黄铜矿浸出时呈现出的反应化学和浸出机理。     

锌精矿常压浸出与加压浸出工艺比较

比较了常压浸出与加压浸出两种工艺的机理、流程、技术经济指标、投资以及存在的问题。试验和生产数据表明,加压浸出在技术上和工艺上都更具有吸引力。     

湿法炼锌浸出工序的工艺改进

介绍了葫芦岛锌厂第一冶炼厂浸出工序的工艺改进过程，通过对加料系统工艺流程、浸出槽排列纵向位置的改进，解决其投料困难，跑、冒、滴、漏严重，设备故障率高等问题。提高了劳动生产率，降低了劳动强度，改善了劳动环境。     

湿法炼锌浸出沉铁探讨

介绍了湿法炼锌的常规浸出法、黄钾铁矾法、针铁矿法沉铁热力学、动力学条件，以及提高湿法炼锌浸出沉铁速度和沉铁效果的影响因素，并结合株冶浸出厂沉铁的现状，提出应采取的措施。     

Improvements in the Ammonium Carbonate Leaching Process During the Treatment of Oxidized Nickel Ores

Based on the experimental data obtained in a volume of solution of 25 dm in a periodic installation for the carbonate-ammonia leaching of Nicaro factory reduced minerals, it was established that the reaction of the oxidation of the Fe (II) up to the moment of maximum cobalt extractions is of zero order. The existing correlation between the constant of speed of oxidation of Ni and Co and the specific mass of speed of air in the different leaching zones according to the behaviour of the iron during its oxidation has been demonstrated. Some alternatives arc suggested to improve the leaching operation with the objective of reaching extraction of cobalt higher than 60% while Ni is at 80%.     

Reproductive history, glucose tolerance, and NIDDM in Hispanic and non-Hispanic white women. The San Luis Valley Diabetes Study

OBJECTIVE: To ascertain whether childbearing would decrease oral glucose-stimulated insulin and C-peptide levels and increase the risk of NIDDM and impaired glucose tolerance in a population of Hispanic and non-Hispanic white women residing in the San Luis Valley of Colorado. Several investigators have related childbearing to subsequent abnormal glucose tolerance. RESEARCH DESIGN AND METHODS: In a population-based case-control epidemiological study, diabetic patients 20-74 yr of age (n = 196) and randomly sampled control women subjects (n = 735) underwent a glucose tolerance test, a physical examination, and an in-person standardized interview. The relations between the live-birth number and fasting and oral glucose stimulated glucose, insulin and C-peptide concentrations, and NIDDM and impaired glucose tolerance were estimated using linear or logistic regression to adjust for extraneous variables. RESULTS: In women selected as control subjects, the live-birth number was related to a significant decrease in the sum of 1- and 2-h C-peptide concentrations (coefficient = -0.077, P < 0.001) and the logarithm of the sum of 1- and 2-h insulin concentrations (coefficient = -0.014, P = 0.02). After adjustment for subscapular skin-fold thickness, the relative odds of NIDDM for the live-birth number, which was small and of borderline significance, diminished (odds ratio = 1.04 for one birth, P = 0.18). Findings were similar for impaired glucose tolerance. CONCLUSIONS: Childbearing was related to lower C-peptide and insulin levels in Hispanic and non-Hispanic women of the San Luis Valley. It had little apparent effect on later risk of NIDDM or impaired glucose tolerance.     

Excess incidence of known non-insulin-dependent diabetes mellitus (NIDDM) in Hispanics compared with non-Hispanic whites in the San Luis Valley, Colorado

Levodopa was released by depolarizing stimuli from rat striata in a transmitter-like manner in vitro and in vivo. Exogenous nanomolar levodopa stereoselectively facilitated the release of dopamine and noradrenaline via presynaptic beta-adrenoceptors in brain slices even under inhibition of aromatic L-amino acid decarboxylase. This facilitation was competitively antagonized by levodopa methyl ester, whereas it was non-competitively antagonized by propranolol. Furthermore, picomolar levodopa stereoselectively potentiated the isoproterenol-induced facilitation of the noradrenaline release. Levodopa methyl ester selectively antagonized this potentiation, while propranolol antagonized both the facilitation by isoproterenol alone and its potentiation by levodopa. The recognition site for levodopa could be differentiated from the carrier proteins for levodopa transport, because nanomolar levodopa methyl ester abolished the levodopa-induced facilitation of the noradrenaline release, whereas a 30 times higher concentration of L-phenylalanine or L-leucine produced no antagonism. Microinjection of levodopa into the nucleus tractus solitarii led to dose-dependent decreases in arterial blood pressure and heart rate in rats in a levodopa methyl ester-sensitive manner. Based on these findings, we propose that levodopa itself is an endogenous neurotransmitter in the CNS.     

The role of dietary fiber in the etiology of non-insulin-dependent diabetes mellitus. The San Luis Valley Diabetes Study

Accuracy of patient positioning and dose delivery in mantle field irradiations was investigated on 29 patients treated between August 1990 and December 1991. Patients were treated in two different centers, University Hospital St. Rafa?l in Leuven and Institut Gustave Roussy in Villejuif, where different techniques and procedures were used. Measurements were performed on 341 portal films and entrance doses were measured in 518 treatment set-ups. The impact of systematic errors occurring during treatment preparation and day-to-day variations on the accuracy of treatment execution were separately analysed. Daily reproducibility, defined as the deviation from the respective mean measured value for a treatment was demonstrated to be good for both the treated volume and the delivered dose and no difference between the two techniques was shown. Comparing the successive portal films of individual patients (reproducibility of a treatment, once it has started), only small day-to-day variations are found: the SD is 3.4 mm for craniocaudal movements and 2.6 mm for lateral movements. For dose delivery very narrow distributions are obtained with SDs of, respectively, 1.5% and 1.85% for the Leuven and the Villejuif group. This suggests that the position of the patient, which is often thought as the critical point in this complex set-up can be done in a very accurate way, regardless of the position used. To assess the global accuracy of the treatment, the actually treated volume and delivered dose were compared with the planned values. Apart from reproducibility this also takes into account the whole preparatory procedure between planning and the start of the therapy (first session).(ABSTRACT TRUNCATED AT 250 WORDS)     

Hazard evaluation of inorganics, singly and in mixtures, to flannelmouth sucker Catostomus latipinnis in the San Juan River, New Mexico

Larval flannelmouth sucker (Catostomus latipinnis) were exposed to arsenate, boron, copper, molybdenum, selenate, selenite, uranium, vanadium, and zinc singly, and to five mixtures of five to nine inorganics. The exposures were conducted in reconstituted water representative of the San Juan River near Shiprock, New Mexico. The mixtures simulated environmental ratios reported for sites along the San Juan River (San Juan River backwater, Fruitland marsh, Hogback East Drain, Mancos River, and McElmo Creek). The rank order of the individual inorganics, from most to least toxic, was: copper > zinc > vanadium > selenite > selenate > arsenate > uranium > boron > molybdenum. All five mixtures exhibited additive toxicity to flannelmouth sucker. In a limited number of tests, 44-day-old and 13-day-old larvae exhibited no difference in sensitivity to three mixtures. Copper was the major toxic component in four mixtures (San Juan backwater, Hogback East Drain, Mancos River, and McElmo Creek), whereas zinc was the major toxic component in the Fruitland marsh mixture, which did not contain copper. The Hogback East Drain was the most toxic mixture tested. Comparison of 96-h LC50 values with reported environmental water concentrations from the San Juan River revealed low hazard ratios for arsenic, boron, molybdenum, selenate, selenite, uranium, and vanadium, moderate hazard ratios for zinc and the Fruitland marsh mixture, and high hazard ratios for copper at three sites and four environmental mixtures representing a San Juan backwater, Hogback East Drain, Mancos River, and McElmo Creek. The high hazard ratios suggest that inorganic contaminants could adversely affect larval flannelmouth sucker in the San Juan River at four sites receiving elevated inorganics.     

复杂氧化铜矿堆浸生产实践

赞比亚某复杂氧化矿采用堆浸方式回收铜资源。但由于当地降雨量大,矿石粉矿率高、且易于泥化等因素,导致浸出渗透性差、生产无法连续,以及矿堆边坡不稳定等问题出现。通过技术创新,实现了全年连续性浸出生产,各项经济指标均得到大幅提升。浸出率由66.41%提高到77.90%,比设计值高出5.9个百分点,每年多产3 000t铜;酸耗由4.61t/t降低到2.87t/t,吨铜成本节约近200美元;同时,闭堆周期由695d降到407d,大大提高了浸出效率。     

气力搅拌浸出槽在黄金选厂的应用

机械搅拌浸出槽是氰化法提金中的关键性设备和工艺实施手段,但由于其传动结构复杂,能耗较高等缺点,在有些黄金选厂已经被气力搅拌浸出槽取代。在简要介绍氰化浸出工艺发展历史的基础上,结合氰化浸出工作原理和工艺影响因素详细分析了气力搅拌浸出槽的结构、工作原理和作业优缺点。在黄金选厂的应用实践表明,气力搅拌浸出槽具有结构简单,易于维修,节能降耗,浸出率高等优点,其应用前景广阔。     

用于热压浸出工艺的高压釜装备研究及工程放大

热压浸出是湿法冶金领域发展至今非常有推广前景的高效工艺,高压釜是该工艺的核心装备与关键技术。系统回顾了中国科学院过程工程研究所多年来利用热压浸出工艺处理难冶金银精矿、高铁闪锌矿、氧化铜矿及红土矿等的研究历程,从实验室小试-扩试-示范工程直至工业生产的途径,分别采用了管式高压釜、空气搅拌高压釜、钛复合板高压釜以及100 m³生产型高压釜,实现了这些难处理矿产资源的高效清洁利用。