Beneficiation of low-grade diasporic bauxite with hydrocyclone

Low-grade diasporic bauxite was treated with hydrocyclone of small cone-angle. The effects of apex diameter, feed pressure and feed concentration on separation indexes were tested, and then the separation process was discussed by hydrokinetics tentatively. The results show that the increase of apex diameter changes the spacial locality of the envelope of zero vertical velocity, resulting in decrease of the ratio of Al2O3/SiO2 in overflow and increase of the recovery of Al2O3 in underflow, while feed pressure and feed concentration have no remarkable effect on the spacial locality of the envelope of zero vertical velocity, however, the separation indexes are improved by the increase of feed pressure, but are worsened by the increase of feed concentration.     

荷叶与修养

一位朋友跟我聊天,说人活的真累,如果能有荷叶那样的修养就好了。我追问荷叶有什么样的修养？她笑着说,你应该想到。     

氧化亚铁硫杆菌在硫化矿物表面的吸附

研究了氧化亚铁硫杆菌在黄铁矿、黄铜矿、方铅矿和闪锌矿表面的吸附情况，结果表明，氧化亚铁硫杆菌在4种硫化矿物表面的吸附无明显选择性；溶液初始pH值对氧化亚铁硫杆菌在4种硫化矿物表面的吸附几乎无影响，但酸性环境有利于吸附的发生；细胞悬浮液浓度为0.1～1.0 g/L、矿浆浓度为15 g/L以上和温度为20～30 ℃是氧化亚铁硫杆菌在4种硫化矿物表面吸附的较适宜条件。扫描电子显微镜检测结果显示，氧化亚铁硫杆菌细胞表面的荚膜是重要的吸附位。红外光谱分析结果表明，氧化亚铁硫杆菌细胞表面含有-OH、-NH₂、C=O、C-O等活性基团，它们在吸附过程中起重要作用。     

Selective adsorption of bacteria on sulfide minerals surface

The adsorption of bacteria on sulfide minerals surface was studied, and the selective adsorption mechanism of cells on the sulfide minerals was investigated by means of FTIR, UVS and XPS. The results show that the three strains of bacteria adsorbed more preferentially on pyrite than on other two sulfide minerals surface at neutral and alkaline pH conditions. FTIR and UVS of three strains of bacteria indicate that there are more functional groups on their surface, such as O---H, C=O, N--H, C--43, and the content of saccharide is more than that of protein. The state of every element on sulfide minerals surface was analyzed by XPS. The empty orbital number of electronic shell of metal ions on minerals surface is important in selective adsorption process, and some stable constants of metal coordinates can be used to explain the contribution of some groups in saccharide of cell wall to the selective adsorption.     

水洗预处理对啤酒废酵母吸附电镀废水中镉的影响

采用扫描电子显微镜、动电电位与红外光谱等分析手段,研究水洗预处理对废啤酒酵母吸附电镀废水中镉影响.结果表明,废啤酒酵母对电镀废水中镉具有较好的咐附性能,水洗预处理使废啤酒酵母吸附能力显著提高,对镉的吸附率由89.85%提高到96.18%.水洗预处理去除了废啤酒酵母中可与镉发生配合作用的可溶相,消除了其与废啤酒酵母对废水中镉的竞争作用,是吸附率显著提高的原因之一.另外,吸附剂吸附位点的增加及荷负电量的增加,也是水洗废啤酒酵母吸附性能得以改善的重要原因.     

苄基丙二酸与羟肟酸类捕收剂组合使用的浮选效果

通过单矿物试验,研究了苄基丙二酸与羟肟酸类捕收剂组合使用时,对赤铁矿和菱锌矿的捕收性能,结果表明：苄基丙二酸与羟肟酸组合使用,能明显提高矿物的回收率,提高浮选效率.当苄基丙二酸∶苯甲羟肟酸（质量比）=4∶6、矿浆pH值为7～9、组合药剂用量为1000g/t时,菱锌矿回收率达到最大值,为75.6%.当组合药剂用量为500g/t、矿浆pH值为4～8、苄基丙二酸∶C5-9羟肟酸（质量比）=2∶8时,赤铁矿回收率达到最大值,为95.6%.从配位化学的角度,分析了苄基丙二酸与羟肟酸组合使用的协同作用机理表明,组合药剂在矿物表面存在穿插吸附和层叠吸附.     

诺卡氏菌在黄铁矿和闪锌矿表面的选择性吸附

研究了诺卡氏菌在不同影响因素条件下,在黄铁矿和闪锌矿表面的选择性吸附。结果表明:培养120 h后诺卡氏菌达到最大生长量;诺卡氏菌在黄铁矿和闪锌矿表面发生明显的选择性吸附,在黄铁矿表面的最大吸附率可达到96.99%,而在闪锌矿表面的吸附率大都在20%以下;诺卡氏菌在两种矿物表面于20 min内即可达到吸附平衡;pH值是影响诺卡氏菌在两种矿物表面发生选择性吸附的关键因素,pH在4~10之间时,选择性吸附现象明显;矿浆浓度超过6 g/L时有利于发生选择性吸附;细胞悬浊液浓度、搅拌速度和温度对吸附效果影响不大,均可产生选择性吸附。扫描电镜检测结果表明,诺卡氏菌细胞表面的菌丝是重要的吸附部位;红外光谱分析结果表明,诺卡氏菌表面含有—OH、—NH2、C O、P O、S O等活性官能团,它们在吸附过程中起重要作用。     

低品位铝土矿在旋流离心力场中的分选试验研究

以铝土矿中赋存的一水硬铝石和硅酸盐矿物间的硬度和密度差异为理论出发点，分析了对之实施分级和常规重力分选的困难所在，提出引入旋流离心力场以强化基于密度差异的分选作用，并对A/S为4.39、磨矿细度为-0.074 mm占61.90%的铝土矿进行了旋流分选试验。试验结果表明，增大水力旋流器的入料动压可同时获得A/S分别为7.64和2.18的底流和溢流产物，此时基于密度差异的分选作用可得到有效强化；增大水力旋流器的沉砂口直径，可以获得A/S为2.08和6.5～7.0的溢流和底流产物，这可为低品位铝土矿的预脱泥处理提供有效的技术途径。     

Removing cadmium from electroplating wastewater by waste saccharomyces cerevisiae

The appropriate condition and scheme of removing cadmium from electroplating wastewater were investigated by adsorption-precipitation method using waste saccharomyces cerevisiae（WSC） as sorbent. Effect factors on biosorption of cadmium in cadmium-containing electroplating wastewater by waste saccharomyces cerevisiae and precipitation process of waste saccharomyces cerevisiae after adsorbing cadmium were studied. The results show that removal rate of cadmium is over 88% after 30 min adsorbing under the condition of cadmium concentration 26 mg/L, the dosage of waste saccharomyces cerevisiae 16.25 g/L, temperature 18℃, pH 6.0 and precipitation time 4 h. Biosorption-precipitation method is effective to remove cadmium in cadmium-containing electroplating wastewater by waste saccharomyces cerevisiae. The SEM, infrared spectroscopy and Zeta-potential of the cells show that chemical chelating is the main adsorption form; electrostatic attraction, hydrogen bonding and van der Waals force all function in adsorption process; and -NH2-,-C=O-,-C=O-NH-,-CH3, -OH are the main adsorption groups.     

草分枝杆菌在硫化矿物表面的选择性吸附规律

研究了草分枝杆菌在黄铁矿、方铅矿、黄铜矿和闪锌矿表面的吸附情况。试验结果表明，草分枝杆菌可以在4种硫化矿物表面发生明显的选择性吸附，在黄铁矿表面吸附情况较好，而在其他3种矿物表面则较差；pH值是影响草分枝杆菌在4种硫化矿物表面发生选择性吸附的关键因素，在pH为4～12之间时选择性吸附现象明显；矿浆浓度在6g／L以上和菌液浓度在0．5—4g／L之间有利于选择性吸附；温度对吸附影响不大；扫描电镜结果显示，草分枝杆菌细胞外膜表面的荚膜是重要的吸附位。研究结果表明，可以在浮选分离中利用草分枝杆菌抑制黄铁矿而优先浮选其余3种硫化矿物。