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Methodology for determining rom size distribution 确定空间大小分布的方法学
Rem-Revista Escola De Minas Pub Date : 2014-12-01 DOI: 10.1590/0370-44672014670184
C. Silva, V. C. G. Souza, J. Koppe
{"title":"Methodology for determining rom size distribution","authors":"C. Silva, V. C. G. Souza, J. Koppe","doi":"10.1590/0370-44672014670184","DOIUrl":"https://doi.org/10.1590/0370-44672014670184","url":null,"abstract":"A methodology to determine the size distribution curve of the ROM was developed in a Brazilian iron ore mine. The size of the larger fragments was determined taking photographs and setting the scale of the images to analyze their dimensions (length of their edges and areas). This was implemented according to a specific protocol of sampling that involves split and homogenization stages in situ of a considerable quantity of ore (about 259 metric tonnes). During the sampling process, larger fragments were separated and smaller size material was screened. The methodology was developed initially in order to preview the performance of a primary gyratory crusher that is fed directly from trucks. Operational conditions of the equipment such as closed and open-side settings could be adjusted previously, obtaining different product size distributions. Variability of size of the fragments affects subsequent stages of crushing and can increase circulating load in the circuit. This leads to a decrease of productivity or recovery of the ore dressing. The results showed insignificant errors of accuracy and reproducibility of the sampling protocol when applied to friable itabirite rocks.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"3 1","pages":"405-412"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87224395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Perspectives for use of hydraulic fracturing in oil and gas production 水力压裂在油气生产中的应用前景
Rem-Revista Escola De Minas Pub Date : 2014-12-01 DOI: 10.1590/0370-44672014670168
Carlos Mouallem, W. D. Sousa, I. E. Cabral, A. Curi
{"title":"Perspectives for use of hydraulic fracturing in oil and gas production","authors":"Carlos Mouallem, W. D. Sousa, I. E. Cabral, A. Curi","doi":"10.1590/0370-44672014670168","DOIUrl":"https://doi.org/10.1590/0370-44672014670168","url":null,"abstract":"Hydraulic fracturing emerges currently, all over the world, as one of the more strategic techniques used by companies in the oil exploitation sector. This technique is characterized by its high productivity and profit in relation to conven tional methods of hydrocarbon exploitation. However, in many countries, as is the case of Brazil, there are several divergences considering the employment of this methodology. Many renowned researchers attest that there are several irreversible environmental impacts generated by the use of this methodology. Among the main environmental impacts are the risk of groundwater level contamination, the risk of surface subsidence, and the risk of the environment contamination with fluids used in the process of the oil and gas extraction.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"1 1","pages":"373-378"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89636809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Potvin stability graph applied to brazilian geomechanic environment 波特文稳定性图在巴西地质力学环境中的应用
Rem-Revista Escola De Minas Pub Date : 2014-12-01 DOI: 10.1590/0370-44672014670171
Michel Melo, C. Pinto, José lldefonso Gusmão Dutra
{"title":"Potvin stability graph applied to brazilian geomechanic environment","authors":"Michel Melo, C. Pinto, José lldefonso Gusmão Dutra","doi":"10.1590/0370-44672014670171","DOIUrl":"https://doi.org/10.1590/0370-44672014670171","url":null,"abstract":"Empirical methods should be restricted to situations similar to the circumstances used for their development. The Stability Graph Method, first proposed by Mathews et al. (1981) and later modified by Potvin (1988), was based on data from Canadian and Australian mines. Therefore, there is no evidence of their use in the Brazilian geomechanical context. The Stability Graph Method is intended to design a stable open stope in mines using the Sublevel Stoping Mining method. The present study investigates the applicability of the methods in Sublevel Stoping Brazilian mines. This is a contribution to the validation of the use of the methods in the Brazilian geomechanical context.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"1 1","pages":"413-419"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76229212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
Diagnosis about iron ore mine haul roads in the Quadrilátero Ferrífero: Itabira Complex case Quadrilátero Ferrífero: Itabira复杂病例中铁矿运输道路的诊断
Rem-Revista Escola De Minas Pub Date : 2014-12-01 DOI: 10.1590/0370-44672014670169
Maíra dos Santos Reis, Waldyr Lopes de Oliveira Filho, E. Oliveira, Gladsney Pena
{"title":"Diagnosis about iron ore mine haul roads in the Quadrilátero Ferrífero: Itabira Complex case","authors":"Maíra dos Santos Reis, Waldyr Lopes de Oliveira Filho, E. Oliveira, Gladsney Pena","doi":"10.1590/0370-44672014670169","DOIUrl":"https://doi.org/10.1590/0370-44672014670169","url":null,"abstract":"Although mine haul roads only provide support for mining activities, their role can be quite significant in any effort to optimize transportation with trucks in open pit mining. In 2009, an inventory about the design, construction and maintenance conditions of these structures in mines in the Quadrilatero Ferrifero was undertaken through a partnership between a large mining company and UFOP. Although the conditions of the roads could be considered broadly satisfactory, several points with potential for improvement were observed. This partnership was recently resumed on enlarged bases for an upgrade, but with a quantitative approach and in a representative mine. The report of this mine haul road diagnosis with a feedback on how we can do more and better for mine haul roads are presented in this work.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"61 1","pages":"421-429"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88476045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
A proposal to find the ultimate pit using Ford Fulkerson algorithm 一个用Ford Fulkerson算法找到最终坑的建议
Rem-Revista Escola De Minas Pub Date : 2014-12-01 DOI: 10.1590/0370-44672014670166
F. R. Souza, Michel Melo, C. Pinto
{"title":"A proposal to find the ultimate pit using Ford Fulkerson algorithm","authors":"F. R. Souza, Michel Melo, C. Pinto","doi":"10.1590/0370-44672014670166","DOIUrl":"https://doi.org/10.1590/0370-44672014670166","url":null,"abstract":"The present study is focused on mining planning with an emphasis on the graph theory model proposed by Lerchs-Grossmann. The original paper published by Lerchs-Grossmann about determination of optimum final pit does not report the computational algorithm to solve the problem. This paper discusses and presents an algorithm based on the maximum flow graph computational work from Ford Fulkerson. The main steps for solving the problem and the results of the two-dimensional models are discussed.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"60 1","pages":"389-395"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75626497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
Mathematical model and supporting algorithm to aid the sequencing and scheduling of mining with loading equipment allocation 辅助装载设备分配采矿排序和调度的数学模型和支持算法
Rem-Revista Escola De Minas Pub Date : 2014-12-01 DOI: 10.1590/0370-44672014670175
A. G. Andrade, M. Santoro, G. Tomi
{"title":"Mathematical model and supporting algorithm to aid the sequencing and scheduling of mining with loading equipment allocation","authors":"A. G. Andrade, M. Santoro, G. Tomi","doi":"10.1590/0370-44672014670175","DOIUrl":"https://doi.org/10.1590/0370-44672014670175","url":null,"abstract":"This paper focuses on the sequencing and scheduling problem of open pit mining, with the allocation of loading equipment considering a medium-term horizon. This study considers the existence of a heterogeneous loading equipment fleet and two types of mineable material, namely ore or waste rock. For the mining of ore, the following requirements are taken under consideration: the mixture quality, a crusher, the processing plant capacity and a stockpile, called ROM stockpile. In this context, we present a mathematical model in mixed integer linear programming, supported by an algorithm that is responsible for moving the time horizon at each model run, aiming to generate mining orders resolved with optimality. Together, these orders describe the loading equipment mining plan.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"162 1","pages":"379-387"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86431800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
An assessment of NRM-20 as a guideline and as an enforcement tool to mine closure in Brazil 评估NRM-20作为巴西矿山关闭的指导方针和执法工具
Rem-Revista Escola De Minas Pub Date : 2014-12-01 DOI: 10.1590/0370-44672014670170
H. Lima, José Cruz do Carmo Flores, Jardel Carvalho Dias
{"title":"An assessment of NRM-20 as a guideline and as an enforcement tool to mine closure in Brazil","authors":"H. Lima, José Cruz do Carmo Flores, Jardel Carvalho Dias","doi":"10.1590/0370-44672014670170","DOIUrl":"https://doi.org/10.1590/0370-44672014670170","url":null,"abstract":"This paper assesses the effectiveness of the NRM-20 as a guideline and a enforcement tool to mine closure in Brazil; assesses the analysis criteria and approval procedures adopted by DNPM to base their decisions on mine closure issues, and looks for gaps in the NRM-20 regarding technical, legal, environmental and socio-economic issues. The study was based on administrative mining proceedings deposed DNPM of Minas Gerais. Were assessed 32 mining proceedings. The study shows clear evidence that DNPM does not have specific criteria to guide the technical analysis of the closure plans required for, which makes the analysis subject to a personal interpretation. This study supports the conclusion that after twelve years of its publication, the NRM-20 lacks in proper regulating and guiding mine closure in Brazil.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"11 1","pages":"367-372"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80444086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Rare earth elements in the international economic scenario 稀土元素在国际经济中的作用
Rem-Revista Escola De Minas Pub Date : 2014-12-01 DOI: 10.1590/0370-44672014670162
Carlos E. P. Ortiz, E. M. Júnior
{"title":"Rare earth elements in the international economic scenario","authors":"Carlos E. P. Ortiz, E. M. Júnior","doi":"10.1590/0370-44672014670162","DOIUrl":"https://doi.org/10.1590/0370-44672014670162","url":null,"abstract":"This article will focus on some relevant aspects of rare earths within the context of the mineral economy. It starts with a conceptual presentation of rare earths addressing both governmental actions, and the private sector. Then, briefly describes their chemical characteristics and their main applications. Finally, more emphasis will be given about some economic aspects: the supply chain structure, the mineral reserves, the production profile, the demand, supply and price analyses, both in the international and Brazilian contexts, and the exports and imports, highlighting China's participation in the rare earth market and concluding with the existence of a Chinese monopoly in the production of this product.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"1 1","pages":"361-366"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78620439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
Solidification thermal parameters and dendritic growth during the horizontal directional solidification of Al-7wt.%Si alloy Al-7wt水平定向凝固过程中的凝固热参数及枝晶生长。% Si合金
Rem-Revista Escola De Minas Pub Date : 2014-09-01 DOI: 10.1590/S0370-44672014000300004
Diego Brito Carvalho, T. Costa, A. Moreira, Maria Adrina Paixão de Sousa da Silva, J. Filho, D. J. Moutinho, O. Rocha
{"title":"Solidification thermal parameters and dendritic growth during the horizontal directional solidification of Al-7wt.%Si alloy","authors":"Diego Brito Carvalho, T. Costa, A. Moreira, Maria Adrina Paixão de Sousa da Silva, J. Filho, D. J. Moutinho, O. Rocha","doi":"10.1590/S0370-44672014000300004","DOIUrl":"https://doi.org/10.1590/S0370-44672014000300004","url":null,"abstract":"O principal objetivo desse trabalho e investigar a influencia dos parâmetros termicos velocidade de solidificacao (VL) e taxa de resfriamento (TR), nos espacamentos dendriticos primarios (λ1) da liga hipoeutetica Al-7%Si, durante a solidificacao direcional horizontal, em regime transiente. Os valores de λ1 foram medidos ao longo do comprimento do lingote e correlacionados com esses parâmetros. A variacao dos espacamentos dendriticos estudados e expressa por meio de funcoes na forma de potencia de VLe TRdadas, respectivamente, por λ1= 55(VL)-1.1e λ1= 212 (TR)-0.55. Um estudo comparativo e realizado entre os resultados encontrados nesse trabalho e aqueles obtidos para a mesma liga quando solidificada direcionalmente nos sistemas verticais ascendente e descendente, sob as mesmas condicoes assumidas. Finalmente, os resultados experimentais obtidos sao comparados com valores fornecidos por alguns modelos teoricos propostos na literatura para analisar espacamentos dendriticos primarios.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"17 1","pages":"265-270"},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85075463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 8
Short-term mining operations in limestone mines–diagnosis and proposition for improvement 石灰石矿山短期开采作业诊断及改进建议
Rem-Revista Escola De Minas Pub Date : 2014-09-01 DOI: 10.1590/S0370-44672014000300008
Candido Francisco de Avila Baptista, Raul Oliveira Neto, Luis Eduardo de Souza
{"title":"Short-term mining operations in limestone mines–diagnosis and proposition for improvement","authors":"Candido Francisco de Avila Baptista, Raul Oliveira Neto, Luis Eduardo de Souza","doi":"10.1590/S0370-44672014000300008","DOIUrl":"https://doi.org/10.1590/S0370-44672014000300008","url":null,"abstract":"This paper deals with a study conducted in a limestone mine located in Cacapava do Sul in the state of Rio Grande do Sul. Themes related to short-term operational planning and unit operations are discussed. We conducted a diagnosis of the practices observed in the mining company under study and recommendations were proposed for change and innovation regarding mining operations. We sought to identify factors that affect productivity as well as actions that could increase the overall efficiency of the unit operations in the \"peak\" production period so that increased market demand could be met without the need for investing in new equipment. The article highlights the difficulties associated with the lack of planning for the mining cycles and with the organization of daily activities. An assignment of daily production to each piece of equipment that is part of the unit operations is suggested in order to optimize operations, thus contributing to the sustainable management of the company.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"14 1","pages":"291-296"},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87412141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
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