Journal of The South African Institute of Mining and Metallurgy最新文献_第8页

Fully automated coal quality control using digital twin material tracking and statistical model predictive control for yield optimization during production of semi soft coking- and power station coal 基于数字孪生物料跟踪和统计模型预测控制的半软焦化电厂煤产量优化全自动煤质控制

IF 0.9 4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2022-09-20 DOI: 10.17159/2411-9717/2002/2022

B. Coetzee, PW. Sonnendecker

引用次数: 1

Petrographic and geochemical characteristics of beneficiated metallurgical coal from the No. 6 Seam, Tshipise sub-basin, Soutpansberg coalfield, South Africa 南非southpansberg煤田Tshipise次盆地6号煤层选矿焦煤岩石学与地球化学特征

IF 0.9 4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2022-09-20 DOI: 10.17159/2411-9717/2061/2022

Moffat Sebola, G. Drennan, N. Wagner

{"title":"Petrographic and geochemical characteristics of beneficiated metallurgical coal from the No. 6 Seam, Tshipise sub-basin, Soutpansberg coalfield, South Africa","authors":"Moffat Sebola, G. Drennan, N. Wagner","doi":"10.17159/2411-9717/2061/2022","DOIUrl":"https://doi.org/10.17159/2411-9717/2061/2022","url":null,"abstract":"The Soutpansberg Coalfield hosts South Africa's hard coking coal reserves. However, coals in this region are understudied compared to other coalfields in the country. This study characterizes the properties of fine-float fraction samples extracted from a wide diameter borehole core in the Makhado Project, Tshipise sub-basin, Soutpansberg coalfield. Conventional analyses were used to determine the coal quality, petrographic composition, mineralogy, geochemistry (including trace element and rare earth element composition), and free swelling index of samples from six coal horizons and three partings from the economic No.6 Seam. The coal samples are classified as medium rank bituminous C coals (0.88 %RoVmr, 0.92 %Rmax) and are highly vitrinitic in composition (97 vol% mineral matter free (mmf)). The samples show strong caking potential (FSI of 9). The total rare earth concentrations range between 570 and 3193 ppm in the ash samples. Preliminary analysis show all but two samples are promising sources of rare earth elements as the total concentrations exceeded the 1000 ppm cut-off grade. Further research is required to confirm these preliminary findings.","PeriodicalId":17492,"journal":{"name":"Journal of The South African Institute of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42035679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Production of Al(HI)-K(I)-Ti(IV)-sulphate-containing leach liquor from metakaolinite-containing ash derived from South African coal fines 用南非细粒含偏高高岭石的灰生产含Al（HI）-K（I）-Ti（IV）-硫酸盐的浸出液

IF 0.9 4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2022-09-20 DOI: 10.17159/2411-9717/1154/2022

A. Collins, C. Strydom, R. Matjie, J. Bunt, J. van Dyk

{"title":"Production of Al(HI)-K(I)-Ti(IV)-sulphate-containing leach liquor from metakaolinite-containing ash derived from South African coal fines","authors":"A. Collins, C. Strydom, R. Matjie, J. Bunt, J. van Dyk","doi":"10.17159/2411-9717/1154/2022","DOIUrl":"https://doi.org/10.17159/2411-9717/1154/2022","url":null,"abstract":"South African discard coal fines and K2CO3 blends were heated in a laboratory-scale rotary kiln to produce ashes for H2SO4 leaching tests. The optimized H2SO4 leaching conditions of 6.12 mol.dm3 (M) H2SO4, solid to liquid ratios 1:5 and 1:10, and 8o°C for 8 hours were used. K2CO3 was added to increase the dissolution efficiency of K. The objective was to determine if the Al present in metakaolinite (Al2O3.2SiO2), the Al, K, and Ti in the alumino-silicate glasses, and the Ti in rutile (TiO2) in the ashes could be selectively dissolved in H2SO4. XRF results show that the ashes formed at 700°C dissolved more efficiently (87% Al, 89% K and 23% Ti) compared to the ashes formed at 1050°C. This can be attributed to the presence of Al2O3.2SiO2, K2CO3 melt, K2CO3 remnants, KAl(SO4)2, and K-aluminosilicate glass in these ashes. XRD results indicate that the ashes prepared at 1050°C contained anorthite (CaAl^Og), microcline (KAlSi3O8), pseudomullite (Al2.SiO2), and silicon spinel (2Al2O3.3SiO2), which are either insoluble or only sparingly soluble in H2SO4. These minerals resulted in the lower dissolution efficiencies of Al and K. Based on the high dissolution efficiencies of Al and K for the ashes produced at 700°C, coal fines blended with K2CO3 could possibly be utilized as feedstocks for the production of aluminium(III), potassium(I), and titanium(IV) and a sulphate-containing leach liquor. Furthermore, the environmental issues and costs associated with the handling and disposal of large volumes of coal fines will also be resolved.","PeriodicalId":17492,"journal":{"name":"Journal of The South African Institute of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44441696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Co-firing of high-ash discard coal and refuse-derived fuel - ash and gaseous emissions 高灰分弃煤和垃圾衍生燃料的共烧——灰烬和气体排放

IF 0.9 4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2022-09-20 DOI: 10.17159/2411-9717/2015/2022

K. Isaac, S. Bada

{"title":"Co-firing of high-ash discard coal and refuse-derived fuel - ash and gaseous emissions","authors":"K. Isaac, S. Bada","doi":"10.17159/2411-9717/2015/2022","DOIUrl":"https://doi.org/10.17159/2411-9717/2015/2022","url":null,"abstract":"This research focuses on the co-firing of discard coal with refuse-derived fuel (RDF) to utilize this abundant resource in South Africa for energy generation and reduce the volume of waste disposed of at landfills. The potential of a coal with a high ash content (> 40%), which is a grade used in some power stations in South Africa, and its combustion compatibility with two different RDFs in terms of emission reductions has been established. Gaseous emissions and ash residues from the combustion and co-combustion of the coal, two different RDFs and coal/RDF blends of different proportion were analysed. One of the RDF samples contained mostly paper (PB) and the other mostly plastic (PL). Co-combustion ash from the discard coal and RDFs showed a decrease in chloride and alkali metal contents as the coal ratio in the blend increased. The slagging propensity of the co-fired blends was found to be very low, while the propensity for fouling decreased from high to medium for all the blends with < 75% RDF. Co-combustion of RDF with coal showed a decrease in SO2 emissions from 387 ppm (discard coal) to 50 ppm for the sample containing 25% coal discard plus 75% PL. A 15% PL to 85% coal blend also reduced NOx emissions from 145 ppm (100% PL) to 88 ppm. The lowest CO2 emission observed was 6000 ppm for the blend of 85% discard coal plus 15% PB. It was established that the most favourable fuel blend that can produce the lowest sulphur emissions if used for power generation is the 25% coal discard plus 75% PL sample.","PeriodicalId":17492,"journal":{"name":"Journal of The South African Institute of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49556477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Novel ceramic composites produced from coal discards with potential application in the building and construction sectors 利用废弃煤生产的新型陶瓷复合材料在建筑和建筑行业具有潜在应用前景

IF 0.9 4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2022-09-20 DOI: 10.17159/2411-9717/2001/2022

O. Eterigho-Ikelegbe, R. Trammell, S. Bada

{"title":"Novel ceramic composites produced from coal discards with potential application in the building and construction sectors","authors":"O. Eterigho-Ikelegbe, R. Trammell, S. Bada","doi":"10.17159/2411-9717/2001/2022","DOIUrl":"https://doi.org/10.17159/2411-9717/2001/2022","url":null,"abstract":"In response to the enormous amounts of coal discard generated during coal mining and preparation, the development of an efficient and sustainable strategic use of this resource is essential. Furthermore, the rising urban population over the next decades is confronted with the depletion of quality raw materials for building components. To this end, this study reports new information on the morphology, water absorption, and flexural strength properties of ceramic composites produced from three different coal discards and polysiloxane pre-ceramic polymer (PCP) resin. In addition, test results relating to the continuous operating temperature, chemical resistance, and efflorescence potential of the composites are presented. The results show that the water absorption and flexural strength of the coal composites, up to 1.94% and 36.46 MPa respectively, exceed the requirements for ceramic and clay roof tiles. The continuous operating temperature of composites is found to be more thermally stable than conventional roofing tiles (concrete and ceramic) between ambient temperature and 600°C. In addition, the excellent chemical resistance of the composites (94.43%-99.98%) compared to conventional roofing tiles (67.82%-99.97%) eliminates the need for additional external coatings. The interesting results documented so far suggest that this technique could be used to produce low-temperature application building products such as bricks, panels, roofing tiles, etc. This new recycling technique offers an excellent opportunity to eliminate enormous volumes of coal discard and to advance the circular economy in the coal industry.","PeriodicalId":17492,"journal":{"name":"Journal of The South African Institute of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48949798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Estimation of coal density using a 3D imaging system: RhoVol 利用三维成像系统估算煤的密度:RhoVol

IF 0.9 4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2022-09-20 DOI: 10.17159/2411-9717/2004/2022

F. Nakhaei, Q. Campbell, M. le Roux, S. Botlhoko

{"title":"Estimation of coal density using a 3D imaging system: RhoVol","authors":"F. Nakhaei, Q. Campbell, M. le Roux, S. Botlhoko","doi":"10.17159/2411-9717/2004/2022","DOIUrl":"https://doi.org/10.17159/2411-9717/2004/2022","url":null,"abstract":"The results of coal sink and float tests are plotted as washability curves. Analysis of these curves indicates the most effective method by which the coal can be cleaned. Sink and float experiments are sampling-dependent, destructive, and use toxic chemicals. The present research introduces an alternative method based on a 3D imaging system called RhoVol, in which the density of individual particles is determined from mass and volume measurements. A quantitative error analysis was conducted on coal sample density measurements obtained by RhoVol, and the main factors influencing the errors identified and investigated. The results show that the drawback of this technique is related to its not being able to detect hidden concavities in the particle, resulting in an overestimation of particle volume. Furthermore, it is difficult to capture the impact of porosity and cracks on the volume of coal particles obtained from 3D silhouette images. This mismatch between the RhoVol data and sink and float test results has led to attempts to apply neural network (NN) and linear regression techniques to produce a fully reliable model for correction and estimation of coal density. The NN approach offers superior predictive capability over linear regression, and the estimated density distribution is in line with the sink and float analysis. The root mean square error in estimation of density using the NN model was less than 0.05 g/cm3.","PeriodicalId":17492,"journal":{"name":"Journal of The South African Institute of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41916544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Flotation of weathered coal discards using a HIP W/O emulsion binder and kerosene 用HIP W/O乳液粘结剂和煤油浮选风化废煤

IF 0.9 4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2022-09-20 DOI: 10.17159/2411-9717/2003/2022

P. M. Mashaba, S. Bada

引用次数: 0

Optimizing cut-off grade considering grade estimation uncertainty - A case study of Witwatersrand gold-producing areas 考虑品位估算不确定性优化边界品位——以威特沃特斯兰德黄金产区为例

IF 0.9 4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2022-08-22 DOI: 10.17159/2411-9717/1403/2022

C. Birch

{"title":"Optimizing cut-off grade considering grade estimation uncertainty - A case study of Witwatersrand gold-producing areas","authors":"C. Birch","doi":"10.17159/2411-9717/1403/2022","DOIUrl":"https://doi.org/10.17159/2411-9717/1403/2022","url":null,"abstract":"Due to grade estimation uncertainty, two statistical errors can occur. The Type I error is where material is classified as ore and mined, despite the true value being below the break-even grade. This material is dilution. The Type II error is where the material is estimated to be below the cut-off grade and is classified as waste, although the true grade is actually above the break-even grade. This material is not mined and is lost. The uncertainty was assumed to follow a normal distribution in a previous study. For this study, estimated block values are compared to those determined after mining (the best estimate of the true grade). This actual data from four mines shows that the uncertainty follows a Laplace distribution. There is no single solution regarding adjusting the cut-off grade away from the break-even grade, considering estimation uncertainty, that could be applied to all gold mines. However, adjusting the cut-off grade downwards (up to 22% for one mine) is noted when optimizing the profit considering grade uncertainties. This type of adjustment could open up significant mining areas and extend the life of the mine.","PeriodicalId":17492,"journal":{"name":"Journal of The South African Institute of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42014965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Economic analysis of rare earth element processing methods for Mountain Pass ore 帕斯山矿石稀土元素加工方法的经济分析

IF 0.9 4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2022-08-22 DOI: 10.17159/2411-9717/1989/2022

T. Uysal

{"title":"Economic analysis of rare earth element processing methods for Mountain Pass ore","authors":"T. Uysal","doi":"10.17159/2411-9717/1989/2022","DOIUrl":"https://doi.org/10.17159/2411-9717/1989/2022","url":null,"abstract":"The increasing demand for rare earth elements (REE) in highly strategic sectors such as hybrid electric vehicles, renewable energy, communication technologies, and the defense industry has made REE production methods important. In recent years, studies on REE have increased rapidly; however there are many studies on REE, there are not enough studies in the literature on the economics of the beneficiation process. RE ores are generally leached after beneficiation by gravity, magnetic and flotation methods. In this study, direct leaching, attrition scrubbing and leaching, and flotation and leaching methods are evaluated economically based on the data for the Mountain Pass (MP) facility. According to the sensitivity analysis performed as a function of capital cost (CAPEX), operating cost (OPEX), and rare earths oxides (REO) recovery, REO recovery has the biggest effect on the process economies. Although the flotation method entails additional investment and operating costs, transportation and operating costs are significantly reduced result of the higher grade and recovery. The flotation method is more profitable, with larger NPV and IRR values and a shorter payback period.","PeriodicalId":17492,"journal":{"name":"Journal of The South African Institute of Mining and Metallurgy","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41383247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

A review of readiness assessments for mining projects 对采矿项目准备情况评估的审查

IF 0.9 4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2022-08-22 DOI: 10.17159/2411-9717/1245/2022

H. Mulder, M. Bekker

引用次数: 0