从镍蛇纹石矿石中浸出Ni,Mg的试验研究

镍蛇纹石矿石中含有大量的Mg,Ni等有价金属,但其开发利用尚处于初级阶段.试验研究了采用硫酸浸出工艺从镍蛇纹石中浸出Ni,Mg.常规硫酸浸出试验结果表明,Mg,Ni浸出率较高,但会导致浸出液酸度大及生产成本高,所以提出了二段逆流浸出新工艺.采用新工艺,Mg,Ni浸出率分别可达到99.3%和97.8%,而且浸出液中游离硫酸的质量浓度可降至1～5 g/L,使最终浸出溶液的pH值保持在1.0～2.0之间,适于下一步净化除杂,同时降低了硫酸用量,是从镍蛇纹石矿石中综合提取Ni,Mg的理想方案.     

粗氢氧化镍制备高品质硫酸镍溶液试验研究

采用氧化洗涤浸出法对粗制氢氧化镍原料中的镍进行了高效浸出试验研究,加入氧化剂过硫酸铵可有效实现主金属镍的浸出,抑制原料中Co、Fe、Mn等杂质金属的浸出,氧化后氢氧化镍纯水洗涤可有效去除粗制氢氧化镍中Na、Mg、Cl离子,浸出液可通过萃取工艺一步分离出高品质硫酸镍溶液,直接用于三元电池材料生产,简化了硫酸镍生产工艺,浸...     

硫化锑矿直接制取锑白的研究

论述了用Cl2 -HCl浸出辉锑矿直接制取锑白的工艺。辉锑矿用Cl2 -HCl体系浸出使Sb以SbCl3 形式溶于浸出液中。浸出液用锑粉还原 ,将Sb5+ 、Fe3 + 还原成Sb3 + 、Fe2 + ,以净化浸出液。净化液稀释后酸度稍有降低 ,使溶液中的Sb3 + 水解 ,各种杂质离子不水解。水解产生的氯氧锑用氨水中和除Cl- ,即可制得产品锑白     

白云石与氟磷灰石的浸出过程热力学

根据化学位图绘制基本原理和方法,分析了Mg2+-Ca2+-H2CO3-H2O、CaCO3·MgCO3-SO2-4-H2O、Ca2+-F--H3PO4-H2O、Ca5(PO4)3F -SO2-4-H2O和Mg2+-H3PO4-H2O体系在常温下的热力学平衡,研究了Ca-Mg-P-H2SO4体系在常温下的溶液-矿物溶解、沉积条件,形象、直观地描述了该溶液体系化学平衡条件及反应进行的限度,为磷矿选矿和湿法浸出过程提供理论依据.结果表明:硫酸可以促进白云石和氟磷灰石的溶解,溶解产物主要是Mg2+、H3PO4,其次是H2PO-4,固相产物主要是硫酸钙晶体;氟磷灰石溶解过程中产生的磷酸在酸性条件下不与溶出的Mg2+反应形成Mg3(PO4)2.     

锌浸出渣协同浸出液气相硫化深度净化

在赤铁矿法炼锌工业中,锌浸出渣锌精矿协同浸出液中的Fe3+、As将极大影响赤铁矿的品质。以锌浸出渣协同浸出液为原料,采用气相硫化的方法,在高酸条件下,完成溶液Fe3+、As的脱除,并使锌、Fe2+完整地保留在溶液中。考察了温度、硫化气体通入量、通入速度等对净化效果的影响。结果表明,在硫化气体为理论通入量的1.2倍,通入速度＜0.3 L/min,反应温度80 ℃的条件下反应,砷的脱除率达95.26%,Fe3+的还原率达到接近100%,铜的脱除率达99.91%,而锌及Fe2+则完整地保留在溶液之中。过程产生的硫化渣量很少,含铜可达30%以上,无需二次处理可直接搭入铜精矿中。     

锂电池正极片浸出液的净化除杂研究

以废旧锂电池正极极片粉浸出液为原料,采用铁粉还原法沉淀铜—硫化钠深度除铜—中和水解法除铁铝—氟化钠除镁工艺流程综合回收有价金属。结果表明,铁粉加入系数1.1时,铜能大量沉淀,再次加入5倍理论量的硫化钠后,铜接近完全沉淀。调节溶液pH=4,反应时间2h,铁和铝接近完全沉淀。除铁后的滤液用氟化钠除去镁离子,设定反应温度80℃、氟化钠用量2.5g/L,镁去除率达99%。除杂后溶液中Cu2mg/L、Mg5mg/L,Al、Fe能控制在6mg/L以内,后续可采用共沉淀法制备碳酸盐前躯体。     

酸浸—萃取—电积法从氧化铜矿中提取铜的研究

含Ｃｕ２６１％的氧化铜矿用硫酸溶液搅拌浸出，浸出液经有机溶液萃取，硫酸溶液反萃取，反萃液电解沉积得到电解铜。进行了浸出、萃取和反萃取条件试验，确定了最佳技术条件和工艺流程。     

汞尾矿同步高效浸出汞锑规律

汞尾矿是汞矿采选冶过程产生的一种危险废弃物,长期堆存对生态环境具有较大危害。另一方面,尾矿中含有的汞、锑也是有价金属。在汞尾矿无害化处理过程中,实现高价值汞、锑的回收,意义重大。开发了硫化钠溶液体系同步柱浸汞尾矿中汞锑新工艺,考察了关键工艺对汞和锑浸出率的影响,获得汞锑同步高效浸出的优化参数,明确了浸出液循环利用和汞锑浓度提升方案。结果表明,经过浸出液循环和二次浸出,汞尾矿中汞和锑浸出率分别可达到96.7%和69.2%,浸出液中汞和锑的浓度可达到22.8 g/L和10.0 g/L。      

硫化铅精矿和废铅膏泥同时浸出过程研究

研究了硫化铅精矿和废铅膏泥同时浸出过程。同时浸出过程涉及两个阶段:(1)在盐酸溶液中,铅精矿中的PbS和废铅膏泥中的PbO、PbO_2、Pb被转化为固体PbCl_2;(2)固体PbCl_2和废铅膏泥中的PbSO_4与MgCl_2反应生成可溶性的配合物MgPbCl_4。第一阶段中的一个关键技术是PbO_2用作PbS的氧化剂,或PbS用作PbO_2的还原剂。两个阶段的总结果是产出了浸出渣和浸出液。从浸出液中可结晶出PbCl_2。第二阶段的过程是铅氯化-湿法冶金中的成熟技术,本研究的重点集中在第一阶段的条件试验。第二阶段采用固定试验条件:浸出温度95℃,溶液中MgCl_2浓度5.5mol/L,浸出时间3h。通过试验确定的第一阶段最佳试验条件:废铅膏泥与铅精矿的质量比3.5∶1,液固比4∶1,溶液pH2.0,转化温度55℃,转化时间4h。试验结果表明,在上述试验条件下,硫化铅精矿和废铅膏泥同时浸出过程的浸出渣含铅达到1.8%,铅浸出率为99.44%。     

富铌渣硫酸浸出液中铌的分离工艺研究

以富铌渣硫酸浸出液为原料,采用氢氟酸溶液沉淀浸出液中的钪、稀土,用TBP萃取HF-H2SO4混酸体系中的铌,使其与钛分离。实验结果表明,氢氟酸加入量为VHF∶VR=1∶4,反应沉淀时间为0.5 h,钪的沉淀率大于91%、稀土沉淀率大于99%;TBP对HF-H2SO4混酸体系中的铌具有很好的萃取性能和铌、钛分离效果,得到了大于90%的氧化铌。     

The effects of magnesium on hydroxyapatite formation in vitro from CaHPO4 and Ca4(PO4)2O at 37.4 degrees C

The effects of magnesium ion on the formation of calcium-deficient hydroxyapatite [Ca9HPO4(PO4)5OH, CDHAp] from CaHPO4 and Ca4(PO4)2O dissolution were investigated using two magnesium sources: Mg3(PO4)2 (chemical system 1) or MgCl2 . H2O (chemical system 2) solutions. Because chloroapatite does not form from aqueous solutions, the use of two magnesium sources facilitated the determination of magnesium's role during synthetic hydroxyapatite formation in vitro and possible related effects during biomineralization. Isothermal calorimetry determined the progress of reactions. Two peaks are observed as heat is evolved during the formation of CDHAp in water at 37.4 degrees C. The nucleation and growth of CDHAp are the corresponding mechanisms. Although the time for complete reaction and total heat-of-reaction DeltaHr remain constant, the height of the first peak is reduced as the concentration of magnesium ion approaches 4 mM in either chemical system. Magnesium does not substitute into CDHAp even though there are calcium vacancies available. Subsequent increases cause the remaining heat peak to broaden and the time required for complete reaction to approach 24 hours as the initial MgCl2 concentration reaches 100 mM. Supersaturation limits chemical system 1 to Mg3(PO4)2 concentrations below 10 mM. A MgCl2 concentration of 3.16 M precludes CDHAp from forming for over 3 months; rather newberyite, MgHPO4 . 3H2O, precipitates. The morphology and surface area of the CDHAp formed in 100 mM MgCl2 solution are comparable to those of CDHAp formed in water. The surface areas are approximately 80 m2/g. Magnesium concentrations below 4 mM only inhibit nucleation whereas those above 4 mM inhibit growth as well. Magnesium phosphate complexes are more inhibitory than magnesium chloride complexes. Increasing the liquid-to-solids ratio or agitation significantly increases the induction period before reaction initiates. Increasing the liquid-to-solids ratio increases the time span for growth whereas increasing agitation decreases the time span for growth. The large inhibitory effect of agitation suggests quiescent systems are more suitable for determining the kinetics of HAp formation. A magnesium inorganic chemical activity (alphaMg = gammaMg[Mg2+]) many times greater than that in biological fluids is required before inhibition of hydroxyapatite formation is realized.     

镁冶金技术的能耗与环境评价

从环境和能耗角度评价国内外的几种主要炼镁方法.通过对比评价得出:以菱镁矿石氯化生产的氯化镁为原料的熔盐电解法具有最小的能量消耗,其次是内加热的硅热法炼镁技术;如果不考虑还原剂的生产能量消耗,内加热的硅热法炼镁能量消耗最少;金属热还原法炼镁对环境影响小,具有极好的发展前景.文章最后提出了我国镁冶金技术发展的建议.     

水氯镁石复盐法脱水工艺

用烧瓶蒸馏装置模拟固定床脱水设备,研究用苯胺盐酸盐作脱水剂的复盐法将水氯镁石(MgCl2.6H2O)脱水制备无水氯化镁(MgCl2)的过程,考察复盐配料比例、保护气含水浓度、热解温度、热解时间等因素对所制备无水氯化镁产品中氧化镁和水分含量的影响,优化用固定床脱水工艺条件。结果表明,完全脱水和脱苯胺盐酸盐的最佳温度和时间分别是300℃与25～30 min和320～350℃与10～20min。最佳配料摩尔比C6H5NH2.HCl∶MgCl2.6H2O为1.1∶1.0。在最佳条件下,可得到合格的无水氯化镁产品MgCl298%～98.6%,MgO 0.03%～0.38%,苯胺盐酸盐0.10%～0.12%,水分0.60%～0.81%。     

流水线镁电解槽电解质导电性研究

研究了不同温度、电解残渣含量以及电解质成分下流水线镁电解槽电解质电导率的变化规律。结果表明,在MgCl2-NaCl-KCl三元体系中,温度升高、电解残渣量增加会导致电导率升高;MgO含量增加、MgCl2浓度增加会引起电导率降低;KCl含量增加、保持MgCl2浓度不变的条件下NaCl浓度增加时电导率先降低后升高。     

1090K下MgCl_2-KCl-CaCl_2三元熔盐体系的密度预测

镁电解工艺中使用的电解质需要具有合适的密度范围.MgCl2-KCl-CaCl2三元熔盐体系是镁电解质的重要基础三元系.使用了新一代溶液几何模型,预测了这一三元系在1 090 K下的密度.首先勘正了标准数据库中的MgCl2-CaCl2熔盐二元系的密度表达式.对已知3个二元系KCl-CaCl2、MgCl2-CaCl2、KCl-MgCl2数据,采用三次式表达的Redlich-Kister关系式拟合得到了它们的超额密度函数.并计算各组分之间的相似系数.最终获得全组分范围内的三元熔盐体系密度分布图.已知成分点的实验值与预测值之间相对误差在2.21%~0.99%之间,这表明了预测结果的可靠性.     

1 090 K下MgCl2-KCl-CaCl2三元熔盐体系的密度预测

镁电解工艺中使用的电解质需要具有合适的密度范围.MgCl2-KCl-CaCl2三元熔盐体系是镁电解质的重要基础三元系.使用了新一代溶液几何模型,预测了这一三元系在1 090 K下的密度.首先勘正了标准数据库中的MgCl2-CaCl2熔盐二元系的密度表达式.对已知3个二元系KCl-CaCl2、MgCl2-CaCl2、KCl-MgCl2数据,采用三次式表达的Redlich-Kister关系式拟合得到了它们的超额密度函数.并计算各组分之间的相似系数.最终获得全组分范围内的三元熔盐体系密度分布图.已知成分点的实验值与预测值之间相对误差在2.21 %~0.99 %之间,这表明了预测结果的可靠性.      

Lime-Soda Softening Process Modifications for Enhanced NOM Removal

In this research, a number of process modifications to the lime-soda softening process were examined, including utilization of high Mg-content lime, addition of MgCl2, and the recycling of softening sludge, in order to improve the removal of natural organic matter (NOM) and reduce the formation of disinfection byproducts (DBPs). Jar test results showed that dissolved organic carbon (DOC) removal increased and trihalomethane (THM) formation was reduced as the magnesium in hydrated lime increased, and was directly correlated with the amount of magnesium removed from the system. However, a dolomitic quick lime hydrated under atmospheric conditions resulted in less effective DOC removal due to a lack of available Mg, and subsequently, less co-precipitation of Mg(OH)2-NOM complexes. The addition of MgCl2 to the raw water also increased DOC removal and reduced THM formation in both the presence and absence of softening sludge, with DOC removal increasing as softening sludge and magnesium dosages increased. As high as 43% removal of DOC was achieved at the stoichoimetric lime-soda ash dose in the presence of 457 mg/L sludge and 7.5 mg/L MgCl2, as compared to only 13% removal in the absence of sludge and MgCl2. The recycling of softening sludge had little or no effect on the hardness and the level of inorganic elements in treated water. The results presented here provide new approaches for improving DBP precursor removal during lime-soda softening without significantly increasing lime and soda ash dosage or the generation of waste sludge.     

NaCl-KCl-MgCl_2熔盐中的CaF_2溶解行为及其对液镁汇集的影响

采用XRD、气冷阴极等手段对CaF_2在NaCl-KCl-MgCl_2电解质体系中的溶解行为及其对液镁汇集状况进行研究。研究表明,CaF_2在NaCl-KCl-MgCl_2熔盐溶解行为表现为CaF_2与MgCl_2反应生成CaCl_2和MgF_2,且随着CaF_2含量的添加,体系氟离子和钙离子浓度逐渐升高,但氟离子增加量相当较慢;CaF_2对液镁汇集的影响表现为与电解质中的MgO结合生成Mg_2OFCl和Mg_2OF_2,降低MgO对液镁汇集的影响,镁在阴极呈现大颗粒的片状结构;随着CaF_2添加量的增加,NaCl-KCl-MgCl_2熔盐体系表面张力逐渐降低,主要受反应产物CaCl_2生成的影响。     

Electrochemical Deoxidation of Titanium in Molten MgCl2–YCl3

Metallurgical and Materials Transactions B - A new electrochemical deoxidation process for Ti, where a mixture of magnesium chloride and yttrium chloride (MgCl2–YCl3) is used as flux, was...     

Magnesium and the heart: antiarrhythmic therapy with magnesium

Magnesium is an essential transmembrane and intracellular modulator of the electrical activity of cardiac cells. This review provides an up-to-date consideration of the cellular and clinical electrophysiological role of magnesium. This ubiquitous element seems to be important from both the theoretical and clinical point of view, because magnesium salts (MgSO4, MgCl2) administered intravenously are particularly effective in those arrhythmias in which the mechanism involves early or delayed after depolarization-induced triggered activity. The authors share the view that I.V. magnesium is the drug of choice in "torsade de pointes" ventricular tachycardia accompanying acquired long QT/QTU syndrome. It is complementary therapeutic agent in digitalis-induced tachycardias. Further studies are needed to elucidate magnesium's mode of action and efficacy in other types of clinical tachyarrhythmias.