Criteria and problems in estimating global lateritic nickel resources

Although two-thirds of the present nickel production is derived from nickel sulfides, lateritic nickel reserves are estimated to be around three times as large as those of sulfides. This discrepancy is largely caused by the mineralogical complexity of lateritic nickel which precludes low-cost beneficiation by conventional physical methods. Nevertheless, lateritic nickel reserves are bound to become increasingly important because of expected metallurgical advances. Lateritic nickel deposits were formed from peridotitic rocks on peneplaned surfaces during a tropical or subtropical climate. The most important deposits were formed during the Tertiary and the lateritization process still continues in deposits situated in the present tropical or subtropical belts. Other deposits, like those in East Europe and Greece, were formed during much older periods (Palaeogene-Cretaceous). The various types of lateritic nickel deposits, covered or uncovered,in situ or transported, are listed and their characteristics briefly mentioned. Large differences exist in depth, grade, specific gravity, and mineralogical composition—the latter especially in the nickel silicate section as opposed to the overlying limonitic section. These large differences exist even within one individual mining area. Because of the mineralogical complexities and highly irregular boundaries of lateritic nickel deposits (especially the upper and lower boundaries of the nickel silicate section), thorough studies are required to determine the mineralogical composition and ratios of the components. Only then may it be possible to specify with confidence the most suitable metallurgical process which has a strong bearing on the cost and consequently the viability of the deposit. This condition makes the exploitability rating in the McKelvey classification diagram relatively more difficult. Because of the quickly changing geological attributes of deposits even within limited areas, it seems necessary to develop various deposit models for many, if not most, individual metallogenic regions. It does not seens justified or practical to use estimation methodologies based on straight extrapolation. This is especially the case when dealing with the young uncovered type of deposit which constitutes the bulk of global resources. Consequently methodologies no. I (areal value estimation. Cargill, Meyer, Picklyk, Urquidi, 1977) and no. 2 (volumetric estimation) are not considered suitable. It is thought that methodology no. 3 (abundance estimation) in conjunction with no. 5 (Delphi estimation) would work satisfactorily but, as could be expected, the most meaningful results should come from a combination of methodologies nos. 4 (deposit modeling), 5 (Delphi estimation), and 6 (integrated synthesis). A classification of leteritic nickel deposit types is proposed. This paper was presented at the International Geological Conclation Program (IGCP) Project 98: “Standards for Computer Applications in Resource Studies” held at Taita Hills, Kenya, November 8–15, 1977.     

1—（2—羟基—3,5—二硝基苯）—3—4（4—苯基—2—噻唑）—三氮稀的合成及其与镍的显

合成了新试剂 1 - (2 -羟基 - 3,5-二硝基苯 ) - 3- (4-苯基 - 2 -噻唑 ) -三氮烯 ,研究了在表面活性剂TritonX - 1 0 0存在下 ,它与Ni2 的显色反应。结果表明 ,在 pH 6.0～ 7.5时 ,Ni2 与该试剂形成配合物 ,其最大吸收峰位于 51 5nm处 ,摩尔吸光系数为 1 .0 8× 1 0 5 L·mol- 1 ·cm- 1 。Ni2 在 0～ 0 .4mg/L内符合比尔定律。方法已用于矿物、合金、钢样中微量镍的测定 ,结果与原子吸收法相符 ,相对标准偏差RSD <5% (n =6)     

茶园土壤不同形态镍的含量及其影响因素

通过自然茶园土壤采样和室内实验分析,探讨浙江、江苏和安徽13个茶园土壤镍的污染状况、形态分布规律以及不同形态镍的含量与土壤镍总量和土壤理化性质的关系。结果表明：部分茶园土壤受到不同程度的镍污染;茶园土壤镍的形态分布有一定差异,按镍的含量多少排序,一般为残渣态＞交换态＞铁锰氧化物结合态＞有机结合态＞碳酸盐结合态;除了交换态以外的所有其他形态的镍含量均随土壤镍含量的增加而显著增加;碳酸盐结合态、铁锰氧化物结合态和残渣态镍含量随土壤pH的升高呈显著增加趋势,而交换态镍则呈减少趋势,但不显著;随土壤有机质含量的增加,铁锰氧化物结合态镍显著减少,而其他形态增加或减少的趋势均不显著;碳酸盐结合态、有机结合态和残渣态的镍含量均随阳离子交换量的增加显著增加;随粘粒含量的增加所有形态中的镍呈增加趋势,但除了残渣态外增加趋势均不显著。     

Usable Values of Nickel Ore and Nickel Concentrate Certified Reference Materials

The preparation and characterisation of three nickel ores and two nickel concentrate certified reference materials are described in this paper. The samples of nickel ore and nickel concentrate were collected from the Hongqiling nickel deposit in Jilin province. The raw materials were crushed and passed through a 2.0‐mm sieve. The rough samples were then ground for 48 hr in a high‐alumina ball mill to a final size of < 0.074 mm. Homogeneity of the samples was tested by X‐ray fluorescence spectrometry (WD‐XRF) and inductively coupled plasma‐atomic emission spectrometry (ICP‐AES). The relative standard deviations (RSD) of results on mass fraction measurements by WD‐XRF were < 1.0% m/m for eighteen components. F‐tests showed that all five samples were homogeneous. Nineteen laboratories contributed with measurement results (2127 in total) for the certification of mass fractions for twenty‐three elements and compounds. Twenty‐three components in the nickel ores and twenty components in the nickel concentrates were characterised as certified values, while the Ni mass fractions ranges from 0.1 to 9.02% m/m in these certified reference materials. These five samples were approved as national certified reference materials by the National Organisation of Reference Materials of China in 2012.     

锍镍试金富集-电感耦合等离子体质谱法测定黑色页岩中的铂族元素

黑色页岩中碳、硫、镍等元素的含量很高,按照常规的锍镍试金熔剂配方不能形成较好的锍扣,影响铂族元素准确定值。本文通过调整试剂配方、优化操作流程等方式建立了黑色页岩中铂族元素的锍镍试金-电感耦合等离子体质谱(ICP-MS)测定方法。结果表明,加入适量硝酸钾可以将铂族元素回收率提高了大约10%。用盐酸溶解锍扣之后,溶液中仍然存在大量黑色沉淀,不易过滤和溶解,趁热在不断搅拌下加入2～3 mL三氯化铁溶液可以在很大程度上减少沉淀量,降低实验操作的难度和不确定性。方法检出限Ru为0.054 ng/g,Rh为0.040 ng/g,Pd为0.40 ng/g,Ir为0.032 ng/g,Pt为0.27 ng/g,Os为0.026 ng/g。精密度和准确度试验表明,该方法稳定可靠,可用于黑色页岩中铂族元素的准确测定。     

Platinum‐Group Element Results for Two Cobalt‐Rich Seamount Crust Ultra‐Fine Reference Materials: MCPt‐1and MCPt‐2

Two Co‐rich seamount crust reference materials, MCPt‐1 and MCPt‐2, were prepared using ultra‐fine particle size milling technique and characterised for the platinum‐group elements (PGEs). The raw material for these two reference materials was collected separately from the Magellan seamounts of the western Pacific Ocean and the seamounts of the central Pacific Ocean by Russian and Chinese scientists. First, they were ground by ball mill to a ?200 mesh powder, then further processed by ultra‐fine jet mill and well‐mixed. The particle size distributions of the samples were tested by a laser particle analyser; the average particle size was 1.8 and 1.5 μm (equal to about 2000 mesh) respectively. The homogeneity of six major and minor elements in these two materials was tested at the milligram level of sampling mass by high‐precision wavelength dispersive X‐ray fluorescence (XRF) spectrometry and at the microgram level of sampling mass by electron probe microanalyser. The homogeneity of more than forty trace elements, including Pt, was tested at the microgram level of sampling mass by LA‐ICP‐MS. Except for Rh, all PGEs were determined by isotope dilution‐ICP‐MS. Platinum in MCPt‐1 and MCPt‐2 was characterised as certified values, whereas the other five PGEs in MCPt‐1 and MCPt‐2 were reported as reference values. In addition, the information values of sixty‐two major, minor and trace elements were obtained by XRF, ICP‐AES and ICP‐MS. The minimum sampling mass for the determination of PGEs was 1 g, while the minimum sampling mass for the determination of the other elements was 2–5 mg.     

内蒙古嘎仙镍钴矿区岩浆作用与成矿

内蒙古嘎仙矿床为大兴安岭北段与岩浆作用有关的大型低品位镍钴硫化物矿床,成矿作用主要与花岗质岩浆作用有关。文章主要对矿区内矿体下盘的花岗岩类(花岗斑岩、长石斑岩、伟晶状花岗岩、黑云母花岗岩)进行了锆石LA-ICP-MS U-Pb定年,获得花岗斑岩的谐和线年龄(125.3±1.1)Ma～(127.5±4.5)Ma,长石斑岩的谐和线年龄为(128.1±2.2)Ma,伟晶状花岗岩的谐和线年龄为(127.9±2.3)Ma,黑云母花岗岩的谐和线年龄为(127.9±1.4)Ma,说明这些花岗岩类主要形成于中生代早白垩世。通过对矿化超镁铁岩、科马提岩、镁铁岩(辉绿岩、玄武岩)、长英质岩(闪长岩、长石斑岩、斜长花岗岩、花岗斑岩、伟晶状花岗岩、黑云母花岗岩)及围岩(大理岩)的主量、微量元素地球化学测试分析,结果表明,与吉峰科马提岩成分相比较,矿化超镁铁岩具有较高的w(SiO_2)(40.53%～54.96%)、w(TiO_2)(0.24%～0.86%)、w(Al_2O_3)(3.58%～10.47%)、w(FeO)(5.30%～8.80%)、w(CaO)(7.35%～13.66%)、w(Na_2O)(0.01%～0.76%)、w(K_2O)(0.02%～0.66%)和w(P_2O_5)(0.06%～0.61%);镁铁岩(包括辉绿辉长岩、玄武岩)铝含量较高,w(Al_2O_3)=16.34%～17.74%;长英质岩类也富铝质(Al_2O_3/(CaO+Na_2O+K_2O)=1.34～1.63),多数岩石属于钙碱性系列。闪长岩与镁铁岩相比,具有较高的硅、铝、钾、钠,较低的铁、镁和钙,微量元素具有大离子亲石元素富集,高场强元素相对亏损的右倾模式;稀土元素具有轻稀土元素富集,重稀土元素相对亏损特征,超镁铁岩类成分点位于N-MORB与OIB范围之间,而镁铁岩和长英质岩类成分点位于E-MORB和OIB之间。镁铁岩落入火山弧玄武岩范围,长英质岩落入火山弧花岗岩+同碰撞花岗岩范围,同属于造山后花岗岩的范围,因此镁铁质岩的形成应属于俯冲-碰撞环境,而长英质岩的形成应属于造山后伸展环境。根据各岩类所含成矿元素和亲流体元素分析,认为含矿热液来自矿区西部的深部,并且构建了嘎仙矿床的成矿模型,即超镁铁岩先期侵位,后期经历了区域的变质变形,最后发生燕山期大规模花岗质岩浆活动及成矿流体的蚀变矿化。     

高频燃烧-红外吸收光谱法测定钼矿石和镍矿石中的高含量硫

高频燃烧-红外吸收法用于分析矿石中低含量硫的测定结果较为准确,但对于高含量的硫,分析结果的准确度不高。本文采用高频燃烧-红外碳硫分析仪测定钼矿石和镍矿石中的高含量硫,选择纯铁屑和钨粒作助熔剂,高温燃烧分解样品,通过实验优化了样品称样量、助熔剂用量、仪器分析时间等测定条件。用国家标准物质进行验证,方法精密度(RSD,n=9)小于1%,加标回收率为96.0%～101.9%;与传统的硫酸钡重量法进行比对试验,测定值的相对误差小于2%。针对不同的矿石样品,研究了实际样品与标准物质的基体匹配问题,消除了基体效应的影响,对于钼矿石和镍矿石样品中含量在1%～35%范围内的硫,均能够准确测定,解决了钼矿石和镍矿石中高含量硫的快速、准确测定问题。     

锍镍试金-电感耦合等离子体质谱法测定硫铁矿中铂族元素

锍镍试金常用于富集常规地质样品中的铂族元素(PGEs);而用于富集硫铁矿中的PGEs鲜有报道。硫铁矿中硫和铁的含量较高,采用常规的试金配方不能得到较好的锍扣,影响下一步样品的溶解和过滤。本文对锍镍试金-电感耦合等离子体质谱法测定硫铁矿中PGEs的流程进行改进。针对硫铁矿中硫和铁含量高的特点,在不减少称样量的情况下,调整常规锍镍试金中的试剂配方,获得了理想的锍扣和熔渣,使锍扣富集PGEs的能力达到最佳,且避免了由于反应时间过长而造成PGEs损失。同时利用硫化铁易剥落和粉化的特点,省去了锍扣的机械粉碎工序,简化了流程,避免了碎扣时的机械损失和样品间可能的交叉污染。结果表明,高含量的铁对PGEs的测定无显著影响。加标回收试验显示PGEs全流程回收率大于94%。按10 g取样量计算,方法检出限分别为Ru 0.018 ng/g,Rh 0.017ng/g,Pd 0.18 ng/g,Os 0.019 ng/g,Ir 0.013 ng/g,Pt 0.11 ng/g。实际样品分析和加标回收试验表明,改进后的锍镍试金-电感耦合等离子体质谱测定流程可以满足大多数硫铁矿中PGEs的测定要求。     

过硫酸铵-丁二酮肟光度法测定红土镍矿中的镍

红土镍矿样品用适宜比例的HCl-HNO3-HF-HClO4混合酸低温消解,待样品溶解完全后在NaOH介质中,以过硫酸铵作氧化剂将Ni2+氧化为Ni4+,使Ni4+与丁二酮肟生成可溶性酒红色络合物,采用分光光度法测定镍的含量。样品溶液中仅通过加入酒石酸钾钠作掩蔽剂,就可消除红土镍矿中其他基体元素对镍测定的干扰,避免了萃取分离操作和有机试剂对环境的污染。在优化的酸碱度、试剂加入顺序及用量、显色时间等实验条件下,镍的线性范围为0～2.0μg/mL,方法检出限为0.1 mg/g,精密度为(RSD)为0.75%～1.69%,加标回收率为95.4%～102.7%。方法用于分析红土镍矿中镍的含量,测定结果与电感耦合等离子体发射光谱法相符。该方法简便,稳定性好,仪器价格低廉,可用于批量红土镍矿样品中镍的快速准确测定。