Partitioning of mineralogical and inorganic geochemical components of coals from Santa Catarina, Brazil, by industrial beneficiation processes
Partitioning of mineralogical and inorganic geochemical components of coals from Santa Catarina, Brazil, by industrial beneficiation processes
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DOI：
10.1016/j.coal.2013.07.002
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发表时间：
2013-09
影响因子：
5.6
通讯作者：
Marcos L. S. Oliveira;C. Ward;C. Sampaio;X. Querol;César M.N.L. Cutruneo;S. R. Taffarel;L. Silva
中科院分区：
文献类型：
--
作者：
Marcos L. S. Oliveira;C. Ward;C. Sampaio;X. Querol;César M.N.L. Cutruneo;S. R. Taffarel;L. Silva
采用低温氧等离子体灰化、X射线衍射和化学分析技术，对巴西南部圣卡塔琳娜州选矿厂的12对原煤和精煤产品中的矿物质和微量元素进行了比较研究，旨在评估选煤对最终煤炭产品矿物学和化学成分的影响。结果表明，矿物质和灰分百分比的大幅减少与从不同矿床开采的煤炭的选矿有关。这些减少伴随着相应煤灰中 Fe2O3 百分比的变化，这是由于矿物质中黄铁矿比例的减少，并且还伴随着 Na2O 百分比的减少，可能是由于粘土矿物内的离子交换。然而，矿物中石英、粘土矿物以及方解石和长石（主要是钠长石）等次要物相的相对比例并未因选矿过程而发生显着变化。选矿产品中大多数微量元素的浓度与相关ROM材料中各自的浓度相似，或者降低到与各煤样的总矿物质百分比相似的程度。这表明主要与富含粘土的矿物质有关。然而，对于大多数样品来说，通过选矿过程，砷和铅的浓度在更大程度上降低，这与黄铁矿的关联一致。许多精煤中的 Ge、U 和 Zr 浓度高于各自的原矿材料，这表明至少对于某些矿床而言，可能与相关煤中富含有机物的部分优先缔合。
Comparative studies of the mineral matter and trace elements in 12 pairs of run-of-mine (ROM) and clean-coal products from beneficiation plants in Santa Catarina, southern Brazil, have been carried out using low-temperature oxygen-plasma ashing, X-ray diffraction and chemical analysis techniques with the aim of evaluating the effect of coal preparation on the mineralogy and chemical composition of the final coal products. The results show that substantial reductions in mineral matter and ash percentages are associated with beneficiation of coals mined from the different deposits. These reductions are accompanied by changes in the percentages of Fe2O3in the respective coal ashes, due to the reduction in the proportion of pyrite in the mineral matter, and also by a reduction in the percentage of Na2O, possibly due to ion exchange within the clay minerals. The relative proportions of quartz, clay minerals, and minor phases such as calcite and feldspar (mainly albite) within the mineral matter are not, however, significantly changed by the beneficiation processes.The concentrations of most trace elements in the beneficiation products are similar to the respective concentrations in the relevant ROM materials, or are reduced to an extent similar to that of the total mineral matter percentage for the respective coal samples. This suggests an association mainly with the clay-rich mineral matter. The concentrations of As and Pb, however, are reduced to a greater extent for most samples by the beneficiation processes, consistent with a pyrite association. Concentrations of Ge, U and Zr are higher in many of the clean coals than in the respective run-of-mine materials, suggesting the possibility of preferential association, at least for some deposits, with the organic-rich fractions of the coals concerned.