Journal of The South African Institute of Mining and Metallurgy最新文献

Energy efficiency in the South African mining sector: A case study at a coal mine in Mpumalanga 南非矿业部门的能源效率:以普马兰加省一个煤矿为例研究

4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2023-10-23 DOI: 10.17159/2411-9717/1788/2023

C.M.D. Majola, K.E. Langerman

{"title":"Energy efficiency in the South African mining sector: A case study at a coal mine in Mpumalanga","authors":"C.M.D. Majola, K.E. Langerman","doi":"10.17159/2411-9717/1788/2023","DOIUrl":"https://doi.org/10.17159/2411-9717/1788/2023","url":null,"abstract":"Energy efficiency is a cost-effective way of both bolstering energy security and limiting the harmful effects of energy use on the environment. Mining is an inherently energy-intensive activity, and the 2008 revision of South Africa's National Energy Efficiency Strategy (NEES) set a target of a 10% reduction in energy consumption by 2015 for the mining sector. In this study, we investigate the effectiveness of the NEES in improving energy efficiency in the South African coal mining sector by surveying energy intensity at a number of operations, and analysing energy efficiency trends and energy use by process and energy carrier at an underground coal mine in Mpumalanga. Most mines surveyed exhibit an increase in energy intensity over time. At the case study mine, the increase was primarily due to increased energy use in the beneficiation and discard reclaiming processes. Trends in energy consumption are a poor reflection of trends in energy intensity, as a decline in energy consumption is most easily achieved by reducing production. A more appropriate metric for energy efficiency at coal mines is energy intensity, defined as energy use per unit of saleable product, relative to a multi-year baseline. The evidence suggests that the NEES has been ineffective in promoting energy efficiency in South African coal mines. We propose that greater success could be achieved by monitoring and reporting on energy intensity at the process level, and by incentivizing energy efficiency gains.","PeriodicalId":17492,"journal":{"name":"Journal of The South African Institute of Mining and Metallurgy","volume":"50 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135460817","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

Optimization of shape factor by the response surface method, and the effect on sphalerite flotation recovery 利用响应面法优化形状因子，研究对闪锌矿浮选回收率的影响

4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2023-10-23 DOI: 10.17159/2411-9717/2645/2023

T. Uysal

引用次数: 0

The needle penetration index for estimating the physico-mechanical properties of pyroclastic rocks 评价火山碎屑岩物理力学性质的针状穿透指数

4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2023-10-23 DOI: 10.17159/2411-9717/1433/2023

S. Kahraman, I. Ince

引用次数: 0

A study of different grinding aids for low-energy cement clinker production 低能水泥熟料生产中不同助磨剂的研究

4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2023-10-23 DOI: 10.17159/2411-9717/2702/2023

S.R.M. Zan, K.E.H.K. Ishak

{"title":"A study of different grinding aids for low-energy cement clinker production","authors":"S.R.M. Zan, K.E.H.K. Ishak","doi":"10.17159/2411-9717/2702/2023","DOIUrl":"https://doi.org/10.17159/2411-9717/2702/2023","url":null,"abstract":"Cement production requires significant energy, and entails high costs and CO2 emissions. This is because the clinker requires very fine grinding. Grinding aids can improve production and fineness and decrease energy consumption by reducing the agglomeration of particles and protecting the balls and liners in the mill. In this study we compare the effects of three different grinding aids on clinker grinding using a ball mill. A commercial grinding additive, triethanolamine (TEA), and two industrial grinding aids (GAA079 and GAA088) were compared by ball milling tests, with additions of 0.05, 0.25, 0.50 and 1.00 wt%. The industrial grinding aids were characterized using gas chromatography-mass spectrometry (GC-MS). Particle size and morphological analyses were performed using SEM and XRD. The best results were obtained with 0.25% GAA088, which has a higher active component of diethanolamine isopropanolamine (DEIPA) than TEA. The unique combination of TEA and DEIPA in GAA088 enhances grinding efficiency and significantly improves the particle size distribution compared to TEA alone.. The grinding aids produced smooth rounded particles, which have a smaller specific surface area, enhancing the quality of the cement. XRD showed no significant structural distortion with or without grinding aids, and it was also found that the grinding aids helped decrease ball coating during grinding. The use of grinding aids can significantly improve clinker production and fineness while decreasing energy consumption, which can help reduce the costs and CO2 emissions associated with cement production.","PeriodicalId":17492,"journal":{"name":"Journal of The South African Institute of Mining and Metallurgy","volume":"44 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135459806","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

The thermal decomposition kinetics of carbonaceous and ferruginous manganese ores in atmospheric conditions 大气条件下含碳和含铁锰矿石的热分解动力学

4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2023-10-18 DOI: 10.17159/2411-9717/2527/2023

S.A.C. Hockaday, F. Dinter, Q.G. Reynolds

{"title":"The thermal decomposition kinetics of carbonaceous and ferruginous manganese ores in atmospheric conditions","authors":"S.A.C. Hockaday, F. Dinter, Q.G. Reynolds","doi":"10.17159/2411-9717/2527/2023","DOIUrl":"https://doi.org/10.17159/2411-9717/2527/2023","url":null,"abstract":"The thermal decomposition of carbonate minerals as pre-treatment before smelting reduces the energy requirement for smelting. It can also make the combustion of fossil fuels for heating unnecassary. Thermal decomposition may become important in reducing greenhouse gas emissions when producing ferromanganese alloys while simultaneously reducing electrical energy demand during smelting. A kinetic reaction rate model for the thermal decomposition of manganese ores is presented, based on published reaction rate kinetics for the decomposition of manganese oxides and calcium carbonate. The model was validated against thermogravimetric data for two carbonaceous manganese ore samples and one ferruginous manganese ore sample. The reaction rate model shows that carbonate minerals in the manganese ores are decomposed at temperatures above 900 °C while pyrolusite is decomposed at temperatures from 450 °C to 500 °C. Mn2O3 decomposes rapidly at 550 °C. Braunite decomposition at temperatures below 1000 °C was negligible. The presence of organic carbon in the samples led to further reduction of the samples during thermal treatment.","PeriodicalId":17492,"journal":{"name":"Journal of The South African Institute of Mining and Metallurgy","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135943481","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

Removal of arsenic and metal ions from acidic effluents via the Fenton reaction method Fenton反应法去除酸性废水中的砷和金属离子

4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2023-10-18 DOI: 10.17159/2411-9717/1863/2023

Y. Wang

引用次数: 0

Mechanism and control of deformation in gob-side entry with thick and hard roof strata 厚硬顶板采空区巷道变形机理及控制

4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2023-10-18 DOI: 10.17159/2411-9717/1707/2023

J.S. Guo, L.Q. MaII, I. Ngo

引用次数: 0

Mechanical activation and physicochemical factors controlling pyrometallurgical, hydrometallurgical, and electrometallurgical processing of titanium ore: A review 钛矿热法、湿法和电法加工的机械活化和理化因素综述

4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2023-10-18 DOI: 10.17159/2411-9717/2082/2023

H.C.S. Subasinghe, A.S. Ratnayake

引用次数: 0

Bord-and-pillar design for the UG2 Reef containing weak alteration layers UG2暗礁含弱蚀变层的Bord和矿柱设计

IF 0.9 4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2023-07-13 DOI: 10.17159/2411-9717/2482/2023

P. M. Couto, D. Malan

{"title":"Bord-and-pillar design for the UG2 Reef containing weak alteration layers","authors":"P. M. Couto, D. Malan","doi":"10.17159/2411-9717/2482/2023","DOIUrl":"https://doi.org/10.17159/2411-9717/2482/2023","url":null,"abstract":"We propose a layout design for the UG2 Reef where weak geological alteration layers are present. The collapse of the Everest platinum mine in South Africa indicated that these layers substantially weaken the pillars. The popular Hedley and Grant pillar strength formula cannot be used where these alteration layers are present. Underground investigations at Everest mine and numerical modelling of the layout were conducted using the TEXAN code and a limit equilibrium model. Simulations of a collapsed area and an intact area allowed for a preliminary calibration of the model. This was subsequently used to explore modified layouts for these ground conditions. An alternative is to compartmentalize the blocks of ore using barrier pillars. The numerical modelling predicted that the barrier pillars appear to remain stable even in the case of large-scale collapses, provided their width exceeds 25 m. Main access routes into the mine can be protected by a double row of pillars at least 15 m wide to provide a safe travelling way. As a cautionary note, these conclusions are based on the model calibration and this needs to be refined in future. Calibration of the limit equilibrium model remains a challenge owing to the large number of parameters involved.","PeriodicalId":17492,"journal":{"name":"Journal of The South African Institute of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42191949","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

Calibration of the limit equilibrium pillar failure model using physical models 用物理模型标定极限平衡矿柱破坏模型

IF 0.9 4区材料科学

Journal of The South African Institute of Mining and Metallurgy Pub Date : 2023-07-13 DOI: 10.17159/2411-9717/2655/2023

R.P. Els, D. Malan

{"title":"Calibration of the limit equilibrium pillar failure model using physical models","authors":"R.P. Els, D. Malan","doi":"10.17159/2411-9717/2655/2023","DOIUrl":"https://doi.org/10.17159/2411-9717/2655/2023","url":null,"abstract":"The limit equilibrium model, used in displacement discontinuity codes, is a popular method to simulate pillar failure. This paper investigates the use of physical modelling to calibrate this model. For the experiments, an artificial pillar material was prepared and cubes were poured using the standard 100 mm χ 100 mm civil engineering concrete moulds. The friction angle between the cubes and the platens of the testing machine was varied by using soap and sandpaper. Different modes of failure were observed depending on the friction angle. Of interest is that significant loadshedding was recorded for some specimens which visually remained mostly intact. This highlights the difficulty of classifying pillars as failed or intact in underground stopes where spalling is observed. The laboratory models enabled a more precise calibration of the limit equilibrium model compared to previous attempts. Guidelines to assist with calibration of the model are given in the paper. The limit equilibrium model appears to be a useful approximation of the pillar failure as it could simulate the stress-strain behaviour of the laboratory models.","PeriodicalId":17492,"journal":{"name":"Journal of The South African Institute of Mining and Metallurgy","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42650193","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