加压氰化全湿法处理低品位铂钯浮选精矿工艺研究

针对前期研究提出的浮选精矿先经湿法预处理而后再加压氰化浸出铂族金属的全湿法新工艺，变动预处理反应过程各种工艺参数，考察了预处理对铜、镍氧化浸出以及对后续铂、钯氰化浸出指标的影响。试验结果表明，浮选精矿经预处理后不仅可有效回收浮选精矿中的铜等有价值有色金属，而且有利于后续加压氰化提取铂钯等贵金属。新工艺实现了全湿法直接处理低品位铂钯硫化浮选精矿的创新。     

难处理金精矿加压氧化预处理

研究了某含硫21.2%、含金40.3 g/t难处理金精矿的加压氧化预处理工艺。通过单因素试验研究加压氧化过程中磨矿细度、反应压力、反应温度、反应时间、搅拌转速及矿浆浓度等对氰化效果的影响,得到易于氰化的加压氧化渣。再通过氰化提金过程中矿浆浓度、氰化钠用量、pH、浸出时间等对金浸出率的影响研究,获得最佳加压氧化预处理工艺条件为：磨矿细度-0.045 mm占95%、反应压力1.6 MPa、矿浆浓度20%、反应温度160 ℃、反应时间240 min、搅拌转速350 r/min。在此条件下,金氰化平均浸出率达到97.3%。     

加压氰化提取金银的试验研究

针对常规氰化法提取金银工艺具有浸出时间长,药剂消耗大等缺点,在浸出环节上采用高压浸出装置,对浮选后得到的精矿进行加压氰化提取金、银试验,采用部分正交析因法对加压氰化进行条件优化试验研究,并结合生产实践对常规氰化和加压氰化进行对比分析和评价。由试验结果可知,当加压温度为55 ℃、压力为0.5 MPa、矿浆浓度32%、加压时间90 min、氰化钠用量为17 mL、氧化钙用量为2 g时,可以获得98.13%的氰化浸出回收率,比常规氰化回收率高出0.07个百分点,说明该方法在生产中使用是可行的。     

加压氰化法提取贵金属的研究进展

氰化法是处理金矿较为成熟的工艺。加压氰化过程通过强化反应动力学,可实现难浸金属的高效浸出,在贵金属湿法提取冶金领域是一新兴技术。分别介绍了加压氰化法处理难浸金矿、失效汽车催化剂、含铂族金属矿物等方面的研究工作及其最新进展。对我国云南大理地区低品位铂钯硫化矿的浮选精矿,采用传统火法造锍熔炼技术工序繁冗、能耗高、污染严重、贵金属易分散损失,经济上难以创效。而采用加压氰化全湿法新工艺,不但贵金属及铜镍等有价金属回收指标高,而且该工艺工序少、周期短、能源低、污染小,为开发利用我国低品位原生铂矿资源提供了一条新技术思路。     

氰化银法生产氰化银钾的生产实践

白银经硝酸溶解后,与氰化钠反应生成氰化银沉淀,氰化银经氰化钾络合溶解生成氰化银钾,氰化银钾溶液经过蒸发浓缩后,进行冷却结晶,氰化银钾晶体经脱水、洗涤和干燥后制成成品.     

含铜金精矿热压预氧化—氰化综合回收金铜试验

对某含铜金精矿进行了热压预氧化—氰化综合回收金铜试验,探讨热压预氧化阶段矿石粒度、时间、温度、氧化分压和液固比对铜浸出率的影响。结果表明,在矿石粒度-44μm占85%、时间2.0h、温度210℃、氧分压0.8 MPa和液固比4∶1的条件下,铜浸出率为98.92%。预氧化渣在矿浆浓度为33%、pH=10~11和氰化钠浓度1‰的条件下浸出24h,金浸出率由常规氰化浸出的48.65%提高到98.41%,氰化钠耗量由常规氰化浸出的33.27kg/t下降至1.67kg/t。实现了金、铜的综合回收。     

某铜金精矿加压氧化-氰化浸出试验研究

本文对某铜金精矿进行了高温加压氧化—氰化工艺试验研究,探讨了浸出时间、浸出温度、氧分压和初始NaCl浓度等工艺参数对铜浸出率的影响以及后续氰化条件对金银浸出率的影响。结果表明,在综合条件下,即粒度-325目占90%、初始NaCl浓度40 g/L、浸出温度180 ℃、氧分压0.6 MPa、液固比5∶1、浸出时间2.5 h以及搅拌速度750 rpm,在氰化条件：振荡氰化、液固比2∶1、NaCN加入量10 kg/t浸铜渣和氰化时间24 h,金、银、铜的浸出率分别为98.3%、94.7%和99.7%。该铜金精矿采用加压酸浸—氰化提取金银铜工艺具有对3种有价金属回收率高、氧化速度快、对矿石中杂质不敏感及对环境污染小等优点,具有较好的工业化前景。     

含铜金精矿的纯氧氰化浸出

含铜金矿普遍存在氰耗高、尾渣金品位高的问题,影响矿山的经济效益。我们通过试验研究,查明了含铜金精矿的纯氧氰化浸出的一般规律,提出了高氰化钠浓度、纯氧或富氧浸出等改进工艺的技术措施,使氰渣中金品位和单位氰耗降低,明显缩短了氰化时间     

某难处理硫化金精矿加压氧化一氰化浸金试验研究

对云南某难处理硫化金精矿进行加压氧化一氰化浸金试验研究,考察了加压氧化各因素对氰化浸金的影响。加压氧化最优条件为：固液比1：4,木质素磺酸钠5g／t,硫酸初始质量浓度10g/L,温度190℃,压力2．0MPa,反应时间4h,搅拌转速450r／min。金精矿经加压氧化一氰化浸出获得了97．55％的较高金浸出率。     

含铜金精矿氰化过程铜氰配位数的计算及意义

简要分析含(高)铜金精矿的处理方法,并通过对氰化溶液中铜氰配位数的理论计算,可以得到不同的氰化钠浓度条件下配位数的变化趋势及大小;根据铜在氰化溶液中的浸出率与配位情况,计算出流程中铜消耗的氰化钠量,对于含铜精矿的氰化生产工艺过程控制具有较大的指导意义。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.