武里蒂卡金矿采用分段空场嗣后充填采矿法,充填骨料选用选矿全尾砂,为科学合理地建设矿山充填系统,本文开展了全尾砂高浓度充填料浆输送性能研究.通过坍落度试验研究分析了充填料浆和易性,并初步确定充填料浆的浓度范围为66％ ～68％.以此为基础,利用流变仪测试充填料浆的屈服剪切应力与黏性系数,计算得出管道单位长度充填料浆流动阻力,为矿山充填管路设计提供必要参数.研究表明,武里蒂卡金矿充填需求量为60～100 m3/h,研究确定全尾砂充填料浆浓度为66％ ～68％,井下充填管道内径150 mm;料浆输送阻力2.69～5.74 kPa/m,采用10 M Pa柱塞泵可将充填料浆水平输送1.7～3.7km,能够很好地满足矿山高浓度充填料浆输送的需求.

采用冷冻结晶工艺对钛白副产硫酸亚铁进行了提纯研究,重点考察了结晶母液循环时镁、锰杂质的累积情况以及它们的去除规律,同时对可能引入体系的钠杂质影响也进行了研究.通过多次结晶可以逐渐降低七水硫酸亚铁晶体中镁、锰杂质含量,但结晶母液的循环会导致体系内镁、锰杂质逐渐累积.利用结晶液与结晶体中镁、锰含量的关系曲线推断得到:当结晶液中镁含量低于298 mg/L时,七水硫酸亚铁晶体中镁质量分数将低于0.025％;当结晶液中锰含量高于761 mg/L时,七水硫酸亚铁晶体中锰质量分数将高于0.05％.另外,结晶法提纯硫酸亚铁时应避免向体系中引入钠离子,否则会导致七水硫酸亚铁晶体中钠杂质含量超标问题.该论文研究结果可以为利用结晶法提纯钛白副产硫酸亚铁提供一定的理论和技术指导.

研究了采用水洗—焙烧—还原酸浸工艺从A药剂钴渣中高效回收钴等有价金属,考察了焙烧温度、浸出时间、浸出温度、硫酸浓度、还原剂用量等对有价金属浸出率的影响.结果表明:钴渣在液固体积质量比5/1、常温下搅拌水洗1 h,然后在500℃下焙烧2 h,最后在80℃下用质量浓度80 g/L硫酸、10 g/L亚硫酸钠浸出1 h,钴浸出率在90％ 以上,锌浸出率在96％ 以上,镉浸出率大于99％,浸出液中的有价金属可高效回收.

采用石灰中和酸性废水的矿山普遍存在氧化钙反应不彻底、污泥沉降性能不理想问题.为了提高氧化钙的利用效率、改善污泥的沉降效果,以某铜矿环保车间的废水为试样,进行了氧化钙直接中和废水工艺条件研究和污泥回流+氧化钙中和废水工艺条件研究.结果表明:①在氧化钙用量为24 g/L、消化时间为20 min、搅拌速度为400 r/min情况下进行氧化钙直接中和试验,反应75 min的料浆pH>6.②在污泥(pH>6)回流比例为40％、氧化钙用量为22.0 g/L情况下进行废水中和,也可将废水的pH调至6以上,且废水中金属离子浓度得到大幅度下降,满足送尾矿库储存的要求.③污泥的回流不仅可以充分利用其中未反应的氧化钙,减少新添氧化钙的用量,还可以改善污泥的沉降性能、提高污泥的固含量,有利于尾矿库回水的澄清.

本文研究了絮凝剂类型、絮凝剂用量和渣浆浓度等对中和渣浆沉降性的影响.结果 表明:选用PAM-3、用量在7.5 mg/L,其絮凝沉降效果相当于现场使用的PAM-110 mg/L,每年可节省药剂成本约13.87万元;中和渣浆的絮凝沉降过程符合Hill1方程,沉降速率呈先增后减的趋势.

利用粉煤灰、膨润土和硅酸钠制备复合除砷吸附剂,研究原料配比、固化温度、固化时间、吸附时间、pH值等对其除砷性能的影响.试验结果表明:制备的除砷吸附剂可将废水中砷浓度从0.51 mg/L降低到0.025mg/L,砷去除率为95.28％,出水达到GB3838-2002《地表水环境质量标准》中Ⅰ类水质的砷浓度限值要求.动态吸附试验的出水砷浓度最低降到0.059mg/L,砷去除率最高达88.43％.吸附剂对砷的吸附等温线能够用Langmuir吸附模型很好的描述,为单分子层吸附.

In order to improve the utilization of copper mine,silica white was prepared using copper tailings as raw material,with the method of alkali melting and sulfuric acid precipitation.The effects of leaching time,the ratio of liquid to solid and SiO2 content on powder leaching rate were investigated.The structure and performance of silica white were characterized by FTIR,XRD,XRF and SEM.The results showed the optimum conditions of the leaching time 5 h,the ratio of liquid to solid 4∶ 1 and the SiO2 content 96%,the leaching rate reached 90%.The product was amorphous material with the composition of hydrated silicon oxide and the content of silicon dioxide was 90.41% which reached the chemical industry standard.

In this paper,the alunite concentration which floated from the tailings of Zijinshan copper ore was used as raw material.The processes of extraction of K and Al elements by acid leaching and alums deep-processing were studied.The results showed that when alunite concentration was roasted at 600 ℃ for 2.5h,the dehydration rate approximated to 100%.When acid leaching temperature was 90 ℃,liquid-solid ratio was 6,and the dosage of sulfuric acid was 1.4 times more than theoretical value,the leaching rate of K and Al were 95.85% and 90.61% respectively.When the alums crystal was roasted at 900 ℃ and washed three times,the content of aluminum oxide reached 96.90%.

The effect of isothermal cooling temperature and holding time at temperature during the austempering cycle was investigated on the mechanical properties of low carbon Si-Mn TRIP steel.The investigated steel which was subjected to the austempering consisted of heating at intercritical temperature of 810 ℃ for 50 min,and quenching in molten salt at 380 ℃ and holding for 20 min obtained three phase mixtures containing bainite,ferrite and retained austenite,and offered higher tensile strength(Rm=843 MPa) and excellent plasticity(A5=31%).

Attapulgite was used to modify the urea-formaldehyde adhesive.The effects of added amount and heat activate temperature on the formaldehyde emission content and bending strength were studied.The results showed that when the added amount of attapulgite was 10%~15% by weight of urea-formaldehyde resin,the formaldehyde emission content decreased by 22.1%,and the bending strength decreased a little.When the heat activation was controlled between the 150-250℃ temperature range,the formaldehyde emission content at least decreased by 23%,and the bending strength approached to the resin filled with flour.

The effect of heating in two-phase region was investigated on the microstructure and properties of low carbon Si-Mn TRIP steel.The trial steel was respectively heated to 750 ℃,780 ℃,810 ℃and 840 ℃ and held for 50 min,subsequently was quickly moved into salt bath at 420 ℃ and held for 1 h,and then oil-cooled to ambient temperature.As a result,the microstructure consisting of bainite,ferrite and retained austenite was obtained.The tensile test results showed that the steel austenitized at 810 ℃ achieved the largest product of multiplying strength by plasticity,i.e.,Rm multiplying A5 equal to 18 590 MPa·% and the largest elongation of 22% as well as higher hardness and impact toughness.

The effects of attapulgite,which modified by formaldehyde scavengers,on the adsorptive capacity of formaldehyde saturated vapor and the formaldehyde emission of urea formaldehyde resin were studied.The results showed that the modified attapulgite could improve the formaldehyde adsorptive capacity and reduced the formaldehyde emission when adding into resin as filler.The best effect on formaldehyde emission was the attapulgite modified by formamide or diethanolamine.