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The NoBLOCK Technology A Major Breakthrough in Wet High Intensity Magnetic Separation (WHIMS) NoBLOCK技术是湿式高强度磁选技术的重大突破
Rem-Revista Escola De Minas Pub Date : 2015-09-01 DOI: 10.1590/0370-44672015680116
José Pancrácio Ribeiro, C. H. T. Ribeiro
{"title":"The NoBLOCK Technology A Major Breakthrough in Wet High Intensity Magnetic Separation (WHIMS)","authors":"José Pancrácio Ribeiro, C. H. T. Ribeiro","doi":"10.1590/0370-44672015680116","DOIUrl":"https://doi.org/10.1590/0370-44672015680116","url":null,"abstract":"Since its introduction in 1963 by G.H. “Jones”, WHIMS MS has proven to be, worldwide, a major technology for separating several types of ore fines from their contaminants. Unfortunately, despite its superb characteristics, even if the best operational procedures are followed, one main issue lasts. It is the blocking of the matrix gaps by oversized particles. Protection screens have been employed to wipe out this blockage, though only partially effective. Creative methods and tools have been developed to facilitate and speed up the cleaning process. But, in fact, along 50 years, the matrix blockage nightmare lingered defying the minds involved with Whims operation. The recent environment demands and the need to reduce costs by recovering ore ultra-fines currently being disposed in tailing ponds, further posed a new challenge. Reportedly these ore ultra-fines, typically below 75 microns, demand smaller gaps for its recovery than today’s bottom limit 1.5 mm. The blockage issue worsens even more and to solve it, Gaustec Magnetism, after two years of research and test work, finally succeeded in developing The Brand New NoBLOCK® Technology presented here.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"10 1","pages":"361-366"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89043015","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: 3
Evaluation of the milling efficiency increase of AISI 52100 steel using niobium carbide addition through high energy ball milling 添加碳化铌高能球磨提高AISI 52100钢铣削效率的评价
Rem-Revista Escola De Minas Pub Date : 2015-09-01 DOI: 10.1590/0370-44672014680189
B. Kuffner, Wellington Silvio Diogo, D. Amâncio, G. Rodrigues, G. Silva
{"title":"Evaluation of the milling efficiency increase of AISI 52100 steel using niobium carbide addition through high energy ball milling","authors":"B. Kuffner, Wellington Silvio Diogo, D. Amâncio, G. Rodrigues, G. Silva","doi":"10.1590/0370-44672014680189","DOIUrl":"https://doi.org/10.1590/0370-44672014680189","url":null,"abstract":"The AISI 52100 is a tool-type steel and is more often used in industry for the production of bearings. After the end of its life cycle, it is discarded or remelted, but both processes are considered expensive. Thus, the possibility of reusing this material through the powder metallurgy (PM) route is considered advantageous, since it transforms a waste into another product. To obtain the starting powders, the AISI 52100 steel scrap was submitted to a process of high energy ball milling, which was milled pure and with 1 and 3 % of niobium carbide (NbC) additions. Those additions were performed with the intention of increasing the milling efficiency of the steel, through formation of a metal-ceramic composite with a ductile-fragile behaviour. To determine the morphology and particle size, scanning electron microscopy (SEM) and particle size distribution tests were used. The results indicated that with the carbide addition, a significant increase in the milling efficiency was achieved, being possible to obtain nanoparticles after 20 hours of milling time.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"7 1","pages":"295-300"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88790336","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: 14
Mine surveying works for the purpose of excavating the remaining reserves of bauxite in the deposit of "Podbracan" 为挖掘“Podbracan”铝土矿剩余储量而进行的矿山测量工程
Rem-Revista Escola De Minas Pub Date : 2015-09-01 DOI: 10.1590/0370-44672014680100
A. Milutinović, Aleksandar Ganić, Thamer Rayes Diyab, R. Tokalić, Meri Ganić
{"title":"Mine surveying works for the purpose of excavating the remaining reserves of bauxite in the deposit of \"Podbracan\"","authors":"A. Milutinović, Aleksandar Ganić, Thamer Rayes Diyab, R. Tokalić, Meri Ganić","doi":"10.1590/0370-44672014680100","DOIUrl":"https://doi.org/10.1590/0370-44672014680100","url":null,"abstract":"Mining projects for mineral resource mining contain in certain cases specific technical and technological solutions, these being the result of the mine’s characteristic spatial position and the geometry of the ore deposit, existing mining works, structures, and terrain relief etc. For the purpose of completion of the mining project, it is necessary to carry out a series of mining and surveying tasks during the pre-project and project stage of mining, as well as during the construction of mining facilities and excavation of mineral resources. Specific features of the project concerning excavation of the remaining reserves of bauxite in the deposit of \"Podbracan\", and in this way the forthcoming mining and surveying works, are displayed by the integration of the underground mining project into the existing mine chambers, infrastructure structures on the terrain surface and into the open pit. Large number of mining and surveying works will follow the completion of this project, but in the meantime, this paper shows the a priory accuracy assessment of the spatial position of the point, it being the exit point to the existing bench of the open pit at the elevation +420m.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"1 1","pages":"323-330"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76976312","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
Evidences of the influence of the detonation sequence in rock fragmentation by blasting – Part II 爆轰顺序对爆破破岩影响的证据。第二部分
Rem-Revista Escola De Minas Pub Date : 2015-09-01 DOI: 10.1590/0370-44672014680218
M. Cardu, J. Seccatore, Alberto Vaudagna, A. Rezende, F. Galvão, J. Bettencourt, G. Tomi
{"title":"Evidences of the influence of the detonation sequence in rock fragmentation by blasting – Part II","authors":"M. Cardu, J. Seccatore, Alberto Vaudagna, A. Rezende, F. Galvão, J. Bettencourt, G. Tomi","doi":"10.1590/0370-44672014680218","DOIUrl":"https://doi.org/10.1590/0370-44672014680218","url":null,"abstract":"This paper shows the work conducted at the Experimental Mine of the Research Center of Responsible Mining of the University of Sao Paulo, taking into account the theoretical issues presented in the first part of the article. The research was performed without changing the production cycle and without resorting to investments in new types of equipment: it has attempted to increase the productivity of the quarry, by lowering production costs and improving the quality of the product. Some Key Performance Indicators (KPIs) were established to monitor the results. A new blast design method, a more appropriate initiation sequence and some simple, inexpensive and effective solutions were identified and applied. The results show that the proper selection of delay timing can be of significant benefit to downstream processes as well as enhanced fragmentation itself.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"59 1","pages":"455-462"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85996895","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: 2
Analysis of the economic feasibility of a mining project due to the presence of natural underground cavities 对存在天然地下空腔的采矿项目进行经济可行性分析
Rem-Revista Escola De Minas Pub Date : 2015-09-01 DOI: 10.1590/0370-44672014680094
Iure Borges de Moura Aquino, H. Lima
{"title":"Analysis of the economic feasibility of a mining project due to the presence of natural underground cavities","authors":"Iure Borges de Moura Aquino, H. Lima","doi":"10.1590/0370-44672014680094","DOIUrl":"https://doi.org/10.1590/0370-44672014680094","url":null,"abstract":"The legislation for the protection and conservation of caves is recent in Brazil. In 2008, the Decree 6.640 was enacted and in 2009, the Normative Instruction No 2 by the Brazilian Environment Ministry (MMA, Portuguese acronyms) was published. Mining operations cause a significant impact on the caves when they are present in or next to the mineral body. The impacts include the suppression of cavities and impacts on physical and bio-speleological stability of the caves. On the other hand, the actual legislation causes a significant impact on the mineable reserves when cavities are present. This article aims to assess the impact of the natural cavities on the feasibility of a mining project, based on the federal legislation, as well as to propose alternatives to combine mining activity with cave protection. For this research, three scenarios of open pit for a hypothetical ore body were considered for the assessments. This paper presents the results achieved for the three and comments on the necessity of researches to conciliate the conservation of the natural underground cavities with the mining activities.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"33 1","pages":"351-360"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81288520","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: 3
The kimberley process certification system - KPCS and diamond production changes in selected African countries and Brazil 金伯利进程认证系统- KPCS和选定的非洲国家和巴西的钻石生产变化
Rem-Revista Escola De Minas Pub Date : 2015-09-01 DOI: 10.1590/0370-44672015680024
E. G. Santos
{"title":"The kimberley process certification system - KPCS and diamond production changes in selected African countries and Brazil","authors":"E. G. Santos","doi":"10.1590/0370-44672015680024","DOIUrl":"https://doi.org/10.1590/0370-44672015680024","url":null,"abstract":"After more than a decade since its creation, the KPCS is undergoing questioning as to efficiency in combating the irregular trade of diamonds, among the countries with significant production for the global market, mainly Angola, the Democratic Re public of the Congo and Zimbabwe. Governments and institutions are considering it to be conducive to serious violations of human rights. In Brazil all activities of the sector have been reduced drastically. It is estimated that there has been a loss in Brazilian production, after implementation of the KPCS rules, in the order of 8.1 million Kts, valued at more than $ 2.0 billion.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"12 1","pages":"279-285"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80241662","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: 3
Ultrasound technique to assess the physical conditions of the Monument to Ramos de Azevedo, city of São Paulo, Brazil 超声技术评估巴西<s:1>圣保罗市拉莫斯·德·阿泽维多纪念碑的物理状况
Rem-Revista Escola De Minas Pub Date : 2015-06-01 DOI: 10.1590/0370-44672015680017
Danielle Grossi, E. A. D. Lama
{"title":"Ultrasound technique to assess the physical conditions of the Monument to Ramos de Azevedo, city of São Paulo, Brazil","authors":"Danielle Grossi, E. A. D. Lama","doi":"10.1590/0370-44672015680017","DOIUrl":"https://doi.org/10.1590/0370-44672015680017","url":null,"abstract":"This paper presents the evaluation of the conservation of the Monument to Ramos de Azevedo through a study of the ultrasound pulse velocity. The Monument to Ramos de Azevedo is of great importance for the history of the city of Sao Paulo (Brazil), because it honors the architect who was fundamental in the architectural and social development of the city. This monument was built with Itaquera Granite, a stone widely used in the cultural heritage of the city, which is more specifically called biotite monzogranite. The equipment used was the V-Meter Mark III and only P waves were used with 54 kHz transducers. Several measurements were taken on the monument and on fresh stone, and the results were compared. Results showed that the stone is in good condition even after changing locations twice because the values are very close to those of the fresh sample. The low values were attributed to internal discontinuities or biotite enclaves, the latter being very common in the Itaquera Granite.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"90 1","pages":"171-176"},"PeriodicalIF":0.0,"publicationDate":"2015-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80476895","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
Magnetometric exploration in intrusive basic with evidence of gold in northern region of the Camaquã Sedimentary Basin (RS) Camaquã沉积盆地北部侵入基性磁化找金证据
Rem-Revista Escola De Minas Pub Date : 2015-06-01 DOI: 10.1590/0370-44672015680074
Alice Marques Pereira, C. Moreira, José Ricardo Melgues Bortolin, Syngra Machado Lopes, A. Nardy
{"title":"Magnetometric exploration in intrusive basic with evidence of gold in northern region of the Camaquã Sedimentary Basin (RS)","authors":"Alice Marques Pereira, C. Moreira, José Ricardo Melgues Bortolin, Syngra Machado Lopes, A. Nardy","doi":"10.1590/0370-44672015680074","DOIUrl":"https://doi.org/10.1590/0370-44672015680074","url":null,"abstract":"Esse estudo consiste na aquisicao de dados magnetometricos na regiao de Sao Sepe (RS), sul do Brasil, com o proposito de avaliar o potencial de mineralizacao aurifera de um gabro, a partir de indicios obtidos em prospeccao geoquimica de sedimentos de corrente previos. O gabro denominado Santa Catarina esta intrudido no Complexo Metamorfico Vacacai, uma sequencia metassedimentar ,onde foram reconhecidas diversas jazidas de ouro. Nesse estudo, foram realizadas nove linhas de magnetometria terrestre, com 1.200 m de comprimento cada, num total de 10.800 m e 720 estacoes de leitura. Os resultados sugerem a presenca de mineralizacoes filonianas em fraturas, algumas das quais sujeitas a acao intemperica, com liberacao e transporte de ouro por acao fluvial e deposicao junto a sedimentos de corrente a jusante do gabro. O mapa de sinal analitico descreve as areas de alta susceptibilidade magnetica dentro de seus limites, coincidentes com lineamentos estruturais nas direcoes NE e E-W, associadas a a ultima das quatro fases de deformacao regional, possivelmente responsavel, tanto por fraturamento e abertura de espacos no gabro, quanto pela remobilizacao de sulfeto e ouro reconhecidamente descritos em diversas jazidas de ouro no âmbito do Complexo Metamorfico Vacacai.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"64 1","pages":"163-169"},"PeriodicalIF":0.0,"publicationDate":"2015-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81087518","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
Study of the thermomechanical behavior of API 5L X80 steel micro-alloyed with Nb-Ti through hot torsion tests 通过热扭转试验研究API 5L X80微合金化Nb-Ti钢的热力学行为
Rem-Revista Escola De Minas Pub Date : 2015-06-01 DOI: 10.1590/0370-44672015680191
F. Martins, M. Machado
{"title":"Study of the thermomechanical behavior of API 5L X80 steel micro-alloyed with Nb-Ti through hot torsion tests","authors":"F. Martins, M. Machado","doi":"10.1590/0370-44672015680191","DOIUrl":"https://doi.org/10.1590/0370-44672015680191","url":null,"abstract":"The controlled rolling of high strength low alloy steel has been widely used in the production of large diameter pipes for the oil and gas industry. The thermo-mechanical control process (TMCP) is used to maximize grain refinement and achieve both higher strength and toughness in the steels. In this sense, API 5L X80 micro-alloyed Nb-Ti steel was submitted to hot torsion tests to evaluate its hot deformation behavior. The critical temperatures (Tnr, Ar3 and Ar1) were obtained by testing with multiple strains in continuous cooling. From the flow stress curves generated in the isothermal tests, it was possible to obtain a critical strain that starts dynamic recrystallization, the peak strain for temperatures ranging from 1150oC to 850oC, and the strain rates at 0.2; 0.4 and 0.8s-1. The results showed that peak and critical stress values increase as the temperature decreases and strain rate increases.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"54 1","pages":"195-200"},"PeriodicalIF":0.0,"publicationDate":"2015-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85738604","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 structural model of the Fábrica Nova region, Santa Rita syncline, Quadrilátero Ferrífero: flanking folds as a folding mechanism Fábrica Nova地区，Santa Rita向斜，Quadrilátero Ferrífero的结构模型:作为褶皱机制的侧翼褶皱
Rem-Revista Escola De Minas Pub Date : 2015-06-01 DOI: 10.1590/0370-44672015680058
D. Rossi, I. Endo
{"title":"A structural model of the Fábrica Nova region, Santa Rita syncline, Quadrilátero Ferrífero: flanking folds as a folding mechanism","authors":"D. Rossi, I. Endo","doi":"10.1590/0370-44672015680058","DOIUrl":"https://doi.org/10.1590/0370-44672015680058","url":null,"abstract":"This study focuses on the eastern flank of the Santa Rita syncline (Dorr 1969), with specific emphasis on the region known as Fabrica Nova. Important iron ore deposits are located on the flanks of this structure, such as Timbopeba, Alegria, Sao Luiz, Tamandua, Almas and Fabrica Nova. The Santa Rita syncline is a fold with N-S axial direction and of subregional scale, with roots in the adjacent basement of the Santa Barbara Complex and sectioned by the Agua Quente thrust fault. The hypothesis of this study is that the structural framework of the region resulted from the superposition of at least three deformation phases on the Ouro Preto nappe. The Fabrica Nova mine, located in the central portion of the study area, is embedded in a synformal structure with a 100/20 trending axis named Fabrica Nova synform. The proposed model to explain the particular structural geometry of this region is based on the flanking folding mechanism (Passchier 2001). This mechanism may have been developed by E-W crustal shortening during the F4 tectonic deformation phase.","PeriodicalId":54498,"journal":{"name":"Rem-Revista Escola De Minas","volume":"1 1","pages":"153-162"},"PeriodicalIF":0.0,"publicationDate":"2015-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85232570","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
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