珍珠岩助滤剂的利用途径

近年来在国外助滤剂生产中,除了传统的天然无机助滤剂——硅藻土外,珍珠岩助滤剂也得到了普遍应用。珍珠岩助滤剂具有较好的过滤性能,较小的容重(60—115kg/m~3),较低的可溶性,孔隙量大(其中等孔隙直径为10μm 左右,硅藻土为7μm),过滤中流率高,密度可调节(通过加热膨胀)以及滤饼密度小等特点。一、用膨胀珍珠岩制取不同性能的过滤材料1.抗磨性过滤材料美国用珍珠岩加     

硅藻土提纯及制备助滤剂研究进展

文章对硅藻土提纯技术及硅藻土制备助滤剂技术的研究进展进行了综述。由于优质硅藻土资源的紧缺,利用硅藻土提纯精土制备助滤剂是行业发展所需,高效、环保的物理提纯技术的应用是中低品位硅藻土提纯关键并值得推广;硅藻土助滤剂焙烧技术已较成熟,开发研究具有特殊性能尤其是方石英含量较低的助滤剂产品是行业发展趋势。     

利用凝灰岩制取助滤剂

这里利用的凝灰岩是指湖南临澧盆地第四纪多孔凝灰岩，它呈白色、疏松土块状，物相主要为火山玻屑，含少量或微量石英、黑云母、斜长石、沸石及粘土等，具有典型的玻屑结构。化学成分具有高硅、富铝、丰钾、低铁等特征，为中酸性岩类，钙碱系列、铝过饱和的流纹质凝灰岩，与一般酸性流纹质凝灰岩相比，该多孔凝灰岩具有轻质多孔和高烧失量等特征，其孔隙度为46.14%～47.49%,微孔孔经范围为0.04～20.00μm，平均堆密度为0.56g/cm3，是一种天然的微米孔级多孔矿物原料。据其物化特性，首次开发出凝灰岩助滤剂。(晓非)利用凝灰岩制取助滤剂@晓…     

硅藻土的改性及深加工利用

本文介绍了硅藻土的起源、结构、性质,综述了国内外硅藻土产品在助滤剂、填料、建筑材料与保温隔热材料、载体方面的应用现状。重点从水处理、橡胶、多孔陶瓷、沥青、造纸、新型建筑材料等方面对硅藻土的深加工利用研究进展进行了综述,并对硅藻土的未来发展进行了展望。     

云南昭通氟中毒区煤、土和水中氟的含量与分布

为探讨云南昭通氟中毒地区环境中氟的含量和分布规律以及氟的来源,在昭通镇雄和威信地区采集了160个煤、黄铁矿结核、煤矸石、黏土、玉米、辣椒、饮用水样品,用高温水解-氟离子选择电极法对样品中的氟进行了分析.结果表明：云南昭通氟中毒区晚二叠世龙潭组主采煤层C5煤含氟量低,平均含氟量为77.13 mg/kg;3个典型氟中毒病区民用煤的平均含氟量为72.56 mg/kg,稍低于中国煤炭平均含氟量〖BF〗（82 mg/kg）, 与世界煤的平均值（80 mg/kg）〖BFQ〗接近.中毒区的煤主要为低氟煤,煤中的氟与灰分关系较为密切.中毒区的拌煤黏土中氟含量一般在367～2 435 mg/kg, 但以含氟量超过600 mg/kg的高氟拌煤黏土为主,平均含氟量为1 084.2 mg/kg.氟中毒区饮用水的含氟量一般低于0.35 mg/L,低于国家饮用水的要求(1.0 mg/L).     

湿法磷酸工艺对磷石膏中可溶磷含量的影响

采用模拟湿法磷酸工艺,研究了湿法磷酸的过滤、洗涤工艺和养晶工艺对磷石膏中可溶磷含量的影响。当萃取反应料浆液固比为2.5:1时,絮凝剂的适宜掺量为12 mg/kg料浆,在料浆中适宜停留时间为3～5 min,得到的磷石膏中可溶磷含量仅为0.48%,与没有添加絮凝剂的磷石膏相比,可溶磷含量降低了57%;洗涤水温度应控制在80℃左右,洗涤液固比(2～2.5):1,洗涤3次,得到的磷石膏中可溶磷含量为0.14%,与现有的工艺相比降低了86%;在磷酸萃取反应之后,过滤、洗涤之前,应增加养晶工艺,养晶温度为85℃,养晶时间1h,得到的磷石膏中可溶磷含量仅为0.6%,与没有养晶工艺的相比降低了39%。     

“多孔硅质岩”开发应用的初步研究

本文介绍了湖北京山“多孔硅质岩”的资源状况及物化性能，探讨了其在水泥、陶瓷、耐火保温材料及啤酒助滤剂等工业领域开发应用的可能性。     

焙烧与生石灰改性对磷石膏中可溶磷含量的影响

磷石膏因含有可溶磷,限制了其在建材领域的应用。以生石灰作为改性剂,研究了不同生石灰/磷石膏质量比及不同焙烧温度下磷石膏中可溶磷含量的变化。采用X射线衍射仪、场发射扫描电镜、酸碱度仪和激光粒度分析仪等仪器对焙烧前后磷石膏的物相组成、微观形貌、酸碱度和粒度分布等进行分析对比。结果表明:当焙烧温度为100~200℃时,磷石膏中的石膏全部转变为烧石膏,磷石膏晶体表面发生破损,导致可溶磷含量随着焙烧温度的升高而逐渐增加;由于生石灰能促进可溶磷转化为难溶物质,在加入改性剂生石灰焙烧后,磷石膏中可溶磷得到有效降低,且随生石灰用量的增加,可溶磷含量不断降低;通过对磷石膏改性焙烧,可获得可溶磷含量极低的磷石膏。这将为磷石膏的资源化利用提供新的指导。      

硅藻土助滤剂及其在彩色显像管荧光粉过滤中的应用

本文介绍了用于彩色显像管荧光粉过滤的硅藻土助滤剂加工工艺及其在荧光粉过滤中的应用。经现场试用,满足了过滤工艺要求,达到了国外同类产品的使用效果。指出原土质量、煅烧温度以及产品粒度乃是影响助滤剂质量及过滤效果的主要因素。     

黑龙沟选煤厂煤泥压滤系统改造实践

针对助滤剂成本偏高的问题,黑龙沟选煤厂对煤泥的粒度组成进行了试验分析,发现助滤剂耗量偏高是由于煤泥中高灰细泥含量偏大所致.为降低助滤剂成本,通过采取新增助滤剂自动加药系统,改变煤泥带式输送机的倾角,更换助滤剂,并优化煤泥粒度组成等措施取得了良好效果:在入料时间不变的情况下,减少助滤剂耗量180 g/t;在加药量不变的情...     

Investigating heap bioleaching: Effect of feed iron concentration on bioleaching performance

This paper describes an investigation into the effect of iron concentration in the leach solution on the bioleaching of a low grade copper ore, where chalcopyrite was the dominant copper sulphide. The concentration of dissolved iron is primarily controlled by pH and the relative proportion of ferric to ferrous iron, with significant jarosite precipitation occurring above pH ≈ 1.8 in a highly oxidised system. The solution pH may be increased by the dissolution of acid soluble gangue and when iron oxidation is significantly higher than sulphur oxidation. The study was approached using two experimental systems. In the former, the leach solution was recycled through an ore bed of low aspect (reactor height divided by diameter) ratio for a portion of the experiment. During the recycle phase, no acid was added to the system and acid consumption by gangue material led to a pH increase (1.6–2.2). The resulting jarosite precipitation reduced soluble iron from 2.5 g/l to less than 250 mg/l. Copper recovery decreased, but not in proportion to the decrease in iron. This was partly attributed to adsorption on, or entrainment within, the jarosites. To study the effect of reduced iron concentration on leach performance under more controlled conditions, bioleaching was performed in packed bed column reactors with feed iron concentrations ranging from 5 g/l to 200 mg/l. Observations indicated an initial decreased rate of copper liberation with reduced iron concentration in the feed. The relationship between available Fe³⁺ concentration and copper liberation was not proportional. However, with time, the liberation of copper became independent of iron concentration in the percolation liquor. Further, the specific rate of copper liberation was consistently below the theoretical value on a basis of ferric iron concentration. The highest values of copper liberation were reported at the lowest iron concentrations. In summary, while increased iron concentration in solution may enhance the initial rate of leaching, mineral availability appears to dominate CuFeS₂ leach kinetics through the majority of the leach. Furthermore, high iron concentrations in solution aggravate jarosite formation with concomitant retention of copper in the ore bed.     

印度芥菜对铀的生理响应与积累特征

为了解印度芥菜对铀的生理响应与积累特征,进行了不同铀浓度（0、1、5、20 mg/kg）胁迫下印度芥菜的盆栽试验。结果表明:印度芥菜生长初期受铀的影响较小,生长时间越长、铀胁迫浓度越高,生长情况受影响越明显;低浓度的铀胁迫可刺激印度芥菜光合色素和可溶性蛋白质的合成,但随着铀浓度的提高,植物光合色素和可溶性蛋白质含量明显下降;铀胁迫导致印度芥菜体内的膜脂过氧化产物MDA的含量随着土壤铀浓度的提高而上升,铀对植物叶片的膜脂过氧化影响显著;印度芥菜对铀的富集量随土壤铀浓度的提高而提高,根部对铀的富集能力远强于茎叶部。因此,印度芥菜对铀污染土壤的植物修复具有潜在的应用价值。     

A screen of some native Australian flora and exotic agricultural species for their potential application in cyanide-induced phytoextraction of gold

The phytoextraction of gold is an exciting new area of research involving the use of plants to extract gold from a low grade ore and waste products. The aim of this study was to screen some Australian native plant species and exotic agricultural species for their potential use in cyanide-induced phytoextraction of gold from a crushed ore body. Plants were grown in an ore body with a gold grade of 1.75 g/ton gold and treated with 0.1 g/kg and 1 g/kg cyanide as aqueous NaCN. The above-ground biomass was harvested one week after treatment and the gold concentration determined. Mean gold concentrations of up to 27 g/ton (d.w.) were found in the plant tissue of Trifolium repens cv. Prestige. Higher gold concentrations were generally found in the stems and older leaves with the lowest gold concentrations in the young leaves. Plants grown in the 1 g/kg cyanide treatment generally had higher concentrations of gold in the plant tissue than plants grown in the 0.1 g/kg cyanide treatment. This study demonstrates the potential use of plants to extract and concentrate gold from a low grade ore and waste products.     

福建某低品位金矿新型浸金剂浸金试验

福建某斑岩型金矿品位低、规模大,金主要以自然金形式存在,可见金的粒度较粗,为高效利用该低品位金矿,开展新型浸金剂金蝉全泥浸出试验和柱浸试验,结果表明：全泥浸出在磨矿细度为-0.074 mm占80%、矿浆浓度25%、加石灰调pH 值11.0左右、初始金蝉浓度为500 mg/L和过程中控制金蝉浓度不小于300 mg/L条件下浸出20 h,金的浸出率为93.43%,金蝉耗量为1.02 kg/t;柱浸在矿石粒度为-30 mm条件下喷淋浸出23天,金累计浸出率和金蝉累计耗量分别为86.54%和1.22 kg/t。     

Antimony Mobilization through Two Contrasting Gold Ore Processing Systems,New Zealand

Antimony, a toxic metalloid similar to arsenic, is present at variable levels in most gold-bearing rocks. Antimony is soluble in the surface environment, so antimony (Sb) mobilization in mine waters is an environmental issue around gold mines. The Reefton gold mine was originally developed in gold-bearing quartz veins; Sb concentrations were low (<100 mg/kg) compared to arsenic (As) concentrations (>1,000 mg/kg), and the mine waters had low dissolved Sb (<0.1 mg/L). A second stage of gold mineralization at Reefton involved brecciation and cataclasis of quartz veins and wall rocks, with addition of stibnite (Sb₂S₃). Processing of this ore has resulted in higher dissolved Sb in mine waters (0.1–1 mg/L), even after water treatment that removes most dissolved As (to 0.01 mg/L) by adsorption to suspended iron oxyhydroxide. Competition between As and Sb for adsorption sites on iron oxyhydroxide particles may have resulted in partial exclusion of the more weakly adsorbed Sb. The high rainfall (2,000 mm/year) at Reefton ensures adequate dilution of mine waters after discharge. The Macraes gold mine has no stibnite, and most Sb is in solid solution in the abundant arsenopyrite (Sb up to 2,000 mg/kg). Pit waters have both Sb and As dissolved up to 0.1 mg/L, partly because of evaporative concentration in a low-rainfall environment. Macraes tailings waters have high As (up to 3 mg/L) but negligible Sb (<0.001 mg/L). Reefton mine gold-bearing concentrate, containing stibnite, is transported 700 km to be processed by autoclave oxidation and cyanidation at the Macraes mine. This introduction of additional Sb to the Macraes site substantially increases the Sb content of the process stream periodically. Tailings from this process have up to 3 wt% Sb, dispersed through As-rich iron oxyhydroxides that are formed in the autoclave. The Sb-rich tailings are strongly diluted (approximately 100:1) by the Macraes tailings, and adsorption of Sb to iron oxyhydroxides in the tailings piles ensures that there has been no increase in the Sb content of the tailings water since the Reefton concentrate has been added at Macraes.     

我国铝用炭素的发展方向及提高其质量的措施

我国铝用炭素工业由于技术水平不高,局部装备落后,致使产品质量难以与世界发达国家相比。表现在预焙阳极的体积密度低、电阻率大,抗压强度低,炭渣脱落度大,净耗高;铝用阴极的抗钠浸蚀较差,热膨胀率较高,电阻率较大,致使电解槽炉底变形,寿命较短。为此探讨了我国铝用炭素的发展方向,并叙述了在工艺技术方面和设备选择方面应采取的措施。     

活化蛇纹石促进磷酸改性高岭土对K+的吸附试验研究

磷酸改性高岭土材料表面附载活性强的氢基团,可以与K+发生化学吸附作用,但吸附过程中交换出来的氢离子逐渐累积会影响吸附反应的进行。通过机械球磨蛇纹石,使其结构中的羟基活化溶出,中和累 积的氢离子,以促进磷酸改性高岭土材料对K+的吸附。考察了球磨转速、磷酸改性高岭土（KP）与活化蛇纹石（MAS）的用量比、吸附时间、硝酸钾初始浓度等因素的影响,试验结果表明：当蛇纹石的球磨转速为500 r/min,KP与MAS的用量比为0.6∶0.4,吸附时间为120 min,初始浓度为300 mg/L时,K+的实际饱和吸附量为30.25 mg/g,达到了工业应用的水平。K+吸附饱和后的KP/MAS在蒸馏水中进行试验时,仅有不到5%的K+被溶 出,在2%的柠檬酸溶液中溶出8 h后K+接近全部溶出,说明产品在水中溶解度较低,而在弱酸性环境下具有较好的缓释特性,有利于植物根部对养分的吸收。     

西南某低品位硫化铅锌矿选矿试验研究

西南某低品位铅锌矿石铅品位为2.99％、锌品位为1.57％,伴生银品位为10.80 g/t,铅、锌均主要以硫化物的形式存在.为高效开发利用该低品位矿石,对原矿分别进行了重液浮沉试验及浮选条件试验研究.结果表明:①针对-12 mm原矿进行重液浮沉试验,在重介质悬浮液密度为2.7 kg/m3时,密度大于2.7 kg/m3产...     

炉渣-粉煤灰地聚合物固化铜污染土的试验研究

利用低钙粉煤灰、炉渣为原料制备的炉渣-粉煤灰地质聚合物（BA-FAG）作为固化剂,开展铜污染土的固化试验研究。通过无侧限抗压强度试验和毒性浸出试验,探讨了养护龄期、固化剂掺量及初始铜离子浓度对BA-FAG固化铜污染土效果的影响,并利用X射线衍射（XRD）分析、扫描电镜（SEM）测试及X射线光电子能谱（XPS）分析等手段进行了表征。结果表明,增大固化剂掺量及养护龄期,可以提高BA-FAG固化铜污染土的无侧限抗压强度（UCS）,以及减少铜离子浸出,而污染土中初始铜离子浓度与固化土的强度负相关,并与毒性浸出浓度正相关;掺入20%和30%的BA-FAG可分别固化浓度不超过6000mg/kg与10000mg/kg的铜污染土,固化土28d的UCS值分别不低于0.358MPa和0.457MPa,且在酸性和中性淋滤下毒性浸出浓度均低于100mg/L;重金属铜在被BA-FAG物理封存过程中主要以Cu2+离子和Cu(OH)2沉淀的形式存在。     

机械力化学法制备钙铝复合材料用于深度脱氟

水体中氟化物含量超标一直是全球关注的环境问题之一,使用含钙物质生成氟化钙沉淀法,出水浓度一般在8 ～9 mg/L,不能满足饮用水中含氟低于1.5 mg/L的世卫标准.为此,本文基于机械力活化的概念,使用行星磨球磨钙铝氢氧化物合成加藤石材料[Ca3Al2 (OH) 12],通过OH-与F-离子交换的新脱氟机理,实现了饮水...