浮碱和结晶的成长分散

在纯碱生产中悬浮床重碱结晶在长时间内不沉降,即产生浮碱。作者在参与联碱模试和工业化试验过程中关注浮碱现象,探讨结晶过程基础、OSLO结晶器分级操作时产品粒径的周期性变化、结晶成长的速度分散、固液分散体系、结晶的团聚对结晶成长的影响,总结出浮碱的产生是由重碱结晶晶胚的成长分散引起。

从碱浮渣中回收碱和银的初步试验

为了降低碱性炼铅法的试剂成本，对其碱浮渣的回收利用工艺进行了初步试验研究。结果表明，当采用热水浸出工艺时，碱浮渣中的钾和钠将主要以氢氧化物、硅酸盐及硫化物形态进入溶液，并以碳酸盐形式回收；对浸出渣进行一次浮选，可回收其中约５２％的银。

盐地碱蓬浮床对海水养殖水体原位修复的效果

[目的]研究盐地碱蓬(Suaeda salsa)由陆地生境转移到浮床盐水生环境后的生长情况及其对海水养殖池塘水体原位修复的效果,为利用盐生植物原位修复海水养殖池塘提供方法。[方法]测定修复期间盐水浮床和陆地两种生境下盐地碱蓬的生长及生理生化指标,并监测海水养殖池塘水体水质。[结果]试验期内浮床生境中盐地碱蓬适应良好,生物量显著增加,其中浮床生境盐地碱蓬根系活力、叶片含氮量分别显著高于同期陆地生境中的盐地碱蓬。水质检测表明,修复后浮床区水体中总氮、总磷、氨氮和化学需氧量分别为3.34,0.20,0.47,0.35mg/L,均明显低于对照区,去除效果良好。[结论]盐地碱蓬从陆地生境转移到浮床盐水生境后可以适应水生环境,并通过根系吸收部分去除水中的氮、磷等污染元素。盐地碱蓬原位修复海水养殖池塘水体具有较好的潜力。

碱蓬浮床对海水养殖尾水中氮磷修复效果研究

海水养殖尾水中总氮、总磷超标是引起沿海水体富营养化的主要原因,为研究碱蓬浮床对海水养殖尾水中氮磷的去除效果,该研究设计加入碱蓬(Suaeda salsa)浮床和不加浮床的两组对比实验,通过比较修复前后碱蓬株高、生物量、含水率、根长以及各部位氮、磷的含量变化,以及水体中总氮(TN)和总磷(TP)的去除效果,探究浮床中碱蓬对总氮和总磷的吸收及其生长特性,验证碱蓬浮床对海水养殖废水中氮、磷等的去除能力。结果表明:浮床中碱蓬株高、鲜重、干重、含水率、根长较修复前均有显著增加,说明浮床中盐生植物碱蓬能够适应含海水养殖尾水水培环境;经碱蓬浮床修复,水体中总氮、总磷均明显下降,其中碱蓬对海水养殖尾水中的总氮总磷去除贡献率分别为16.10%和78.15%,浮床中碱蓬会在叶片和根系中积累氮磷。

铜硫无碱等可浮工艺分选秘鲁某铁多金属矿深部矿石

对秘鲁某铁多金属矿含Cu 0.127%、Au 0.08 g/t、S 2.08%、Fe 40.56%的深部矿石进行了选矿工艺试验研究。该矿原设计选矿工艺流程为铜硫混选—铜硫分离—混选尾矿磁选回收铁,存在铜硫分离难度大、石灰用量高和分选指标不理想等问题。针对原流程存在的问题,根据矿石性质,采用铜硫等可浮—硫浮选—磁选和铜硫等可浮—磁选—铁精矿浮选脱硫两种原则工艺流程进行试验研究,铜硫等可浮分选时,采用选择性的铜捕收剂BK306在无碱条件下将铜和部分易浮硫化物浮出,然后进行铜硫分离回收铜、金;最后通过磁选从浮选尾矿中回收铁。通过铜硫等可浮(粗精矿再磨精选分离)—硫强化浮选—磁选和铜硫等可浮(粗精矿再磨精选分离)—磁选—铁精矿强化浮选脱硫两种试验方案的工艺流程和闭路试验指标的对比分析,最终确定了铜硫等可浮(粗精矿再磨精选分离)—磁选—铁精矿强化浮选脱硫的工艺流程,闭路试验获得含铜19.68%、含金8.26 g/t、铜回收率73.19%、金回收率41.83%的铜精矿,含硫35.58%、硫回收率26.02%的硫精矿,以及含铁69.23%、含硫0.16%、铁回收率91.40%的铁精矿。该工艺既可实现矿石中伴生有价金属铜、金的高效回收,又能显著降低铜硫分离所需的石灰用量,并保证后续磁选作业获得含硫低、铁品质较好的铁精矿。

无碱等可浮工艺分选秘鲁某金铜铁多金属矿石

对秘鲁某含Cu 0.12%、Au 0.12 g/t、S 2.60%、Fe 45.52%的金铜铁多金属矿石进行了选矿工艺优化试验研究。该矿石原设计选矿工艺流程为铜硫混选—铜硫分离—混选尾矿磁选回收铁,存在铜硫分离难度大、石灰用量高和分选指标不理想等问题。针对原流程存在的问题,提出采用铜硫等可浮—铜硫分离—难选硫强化浮选—浮选尾矿磁选回收铁的优化工艺流程。铜硫等可浮分选时,在无碱条件下采用选择性的铜捕收剂BK306将铜和部分易浮黄铁矿等硫化矿物浮出,并进行铜硫分离回收铜、金;然后采用活化剂和强力捕收剂强化浮选脱除矿石中的难浮硫化物;最后通过磁选从浮选尾矿中回收铁。该优化工艺既可实现矿石中铜、金等有价金属的高效回收和硫的脱除,又能显著降低铜硫分离所需的石灰用量,并保证后续磁选作业直接获得含硫低、铁品质较好的铁精矿。闭路试验获得铜品位20.10%、金品位15.29 g/t、铜回收率68.42%、金回收率49.07%的铜精矿,硫品位30.78%、总硫回收率84.05%的硫精矿以及铁品位68.88%、含硫0.18%、铁回收率90.57%的铁精矿。与原工艺相比,优化工艺的铜精矿铜品位和铜回收率分别提高2.49和10.25个百分点,铜精矿中金品位和金回收率分别提高5.27 g/t和17.05个百分点,硫回收率提高1.78个百分点。实现了矿石中铜、金、硫、铁的高效综合回收。

碱性直接炼铅法的应用

在比较了几种最新的直接炼铅法的基础上，着重地介绍了碱性直接炼铅法的原理、工艺流程及其特点，并报道了该法在银精矿处理中的应用研究情况。

碱蓬对富营养化海水养殖水体中氮磷的去除研究

采用人工模拟试验的方法,通过设置5种浓度梯度的富营养化水体净化实验,比较研究了盐生植物碱蓬对不同程度富营养化海水养殖水体中氮、磷的净化效果和去除能力。结果显示,碱蓬在低富营养化水体中均可生长,在高营养化水体中需要一定的适应期适应后才可以良好生长;且碱蓬对水中的氮、磷均表现出良好的净化效果,浓度分别由初始的0.68~8.02 mg/L和0.00~3.12 mg/L降至0.37~2.36 mg/L和0.00~1.70 mg/L;对水体盐度的降低也有一定的作用,由初始的3.2%降至2.6%~2.9%;实验结果为利用盐生植物修复海水养殖富营养化水体的模式和机理的深入研究提供了科学依据。

Interaction mechanism of ferrate(Ⅵ) with arsenopyrite surface and its effect on flotation separation of chalcopyrite from arsenopyrite

Potassium ferrate(K_(2)FeO_(4)) was used as a novel environmental-friendly depressant,and its inhibition effect on flotation performance of arsenopyrite and chalcopyrite using potassium ethyl xanthate(PEX)as a collector was investigated by flotation experiments,contact angle measurements,adsorption measurements,localized electrochemical impedance spectroscopy(LEIS)measurements,and X-ray photoelectron spectroscopy(XPS)analyses.The results showed that K_(2)FeO_(4)strongly depressed arsenopyrite in a pH range of 4−11,and the flotation separation of chalcopyrite from arsenopyrite could be realized in the presence of 5×10^(−4)mol/L K_(2)FeO_(4)and 5×10^(−5)mol/L PEX at pH 8 or 10.In the presence of K_(2)FeO_(4) and PEX,the contact angle and the xanthate adsorption capacity of arsenopyrite decreased significantly.LEIS measurements showed that the addition of ferrate could significantly increase the impedance of the arsenopyrite surface.XPS analyses further confirmed that ferrate accelerated the oxidation of arsenopyrite surface.

Potential control flotation of galena in strong alkaline media

The electrochemical oxidation of galena in collectorless and collector flotation systems, particularly in strong alkaline media, was studied. The results show that, with pH value higher than 12.5 and potentials below 0.17 V, the oxidation products of galena are elemental sulfur and HPbO - 2. Elemental sulfur was present on the mineral surface in excess of oxidized lead species due to dissolution of HPbO - 2, which is beneficial to the flotation of galena. Under the same conditions, sphalerite and pyrite were depressed as a result of significant surface oxidation. Diethyldithiocarbamate (DDTC) was found to be the most suitable collector for galena flotation in strongly alkaline media. The very potential produced hydrophobic PbD 2-the surface reaction product of DDTC with galena, is 0 to 0.2 V. Meantime DDTC can depress the surface over oxidation of galena. Investigations also indicate that, in the range of -0.9 V to 0.6 V, hydrophobic PbD 2 can be firmly adsorbed on galena.

Studies of community structure and seasonal dynamics of planktonic copepods in saline-alkaline ponds

Species abundance and seasonal succession of copepods in saline-alkaline ponds were studied in Zhaodian Fish Farm, Gaoqing County, Shandong Province, from 5 April 1997 to 1 September 1998. The results indicated that in the conditions of salinity ranging from 1.36 to 20 g/L, total alkalinity changing from 2.4 to 7.2 mmol/L and pH 8–9, zooplankton in saline-alkaline ponds was composed of freshwater salt-tolerated species or halophile species, some of which are halobiont species and usually occurs in freshwater. In our study, copepods were predominant in many fish-culture ponds and all control ponds without fishes in spring, late autumn and early winter. Dominant species of copepods were Sinocalanus tenellus, Cyclops vicinus, Thermocyclops taiho- kuensis. The biomass of copepods in the control ponds without fishes was higher than that of the fish-culture ponds.