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By D. E. M. Plaumann

"The wet grinding of asbestos has attracted the attention of engineers for many years as a means of improving fibre liberation from the ore. Today, added impetus for wet grinding has resulted from a need to minimize worker exposure to asbestos dust in conventional dry mills using air, as well as a need to provide a cleaner, technically superior fibre for use by product manufacturers. However , high viscosities of asbestos slurries create transport and grinding difficulties which have been a factor impeding use of a wet grinding process.Laboratory evaluation of reagents to reduce viscosities of asbestos slurries found that one reagent, XFS-4272.00, reduced the viscosity of a 35% (by weight) slurry by 75%. The impact of XFS-4272.00 on actual grinding parameters were evaluated using a pilot plant rod mill. Slurries containing 78% solids and XFS-4272.00 were successfully milled and asbestos fibres from that milling compared favourably in liberation and relative surface area to asbestos fibres obtained from milling a 4% slurry without additives.IntroductionAlthough the use of asbestos has been declining over the last few years, the large deposits of chrysotile in eastern Canada (Quebec in particular) remain very important. Asbestos production in Canada stands ninth in volume for mineral production with over 740 000 tonnes produced in 1985. Of this quantity, 722000 tonnes were exported with a value of $446 million . Canada is second in world production of asbestos behind the U.S.S.R ."

Jan 1, 1988

Arguably the SMC Test® has become the most popular laboratory hardness test in the world with over 17,000 tests having been completed to date, covering over 650 different ore bodies. It is now routinely used in design, optimisation and orebody profiling projects. The test is unique in that from relatively small amounts of drill core it simultaneously provides parameters that are used in simulation modelling of AG/SAG and crushing circuits as well as work indices that are used in power-based equations for predicting the specific energies of AG/SAG/Crushing and HPGR circuits. The very large data base that has been accumulated has provided the opportunity to study the differences in variability from deposit to deposit. This paper describes and discusses the trends that have become apparent from the study of this data base. Recommendations for appropriate selection of sample numbers are also made which are based on these trends.

Jan 1, 2012

By P. Hr?enjak

Two groups of methods are usually used in design procedures of underground excavation of dimension stone: the analytical and numerical methods of analysis. In all of these methods the in situ rock mass strength represents the main problem. This is due to massive rocks in dimension stone deposits, consisting of large blocks of rock separated with particular discontinuities, for which the Hoek-Brown empirical criterion, developed for jointed rock masses, cannot be realistically used to estimate rock mass strength, especially for a particular block of rock mass or a particular pillar. On the basis of the regular underground excavation process of dimension stone by separating blocks with the flat jack application, we developed the in situ flexural strength testing method. We carried out numerical analyses and evaluation of uncertainty of measurement in order to validate the in situ flexural strength testing method. On the basis of very good validation results, as well as results of the in situ flexural strength testing of exploitable layers on the ?Kanfanar? quarry, we introduced a new coefficient of reduction, which can be used for correction of other strength parameters determined by laboratory testing for obtaining a realistic value of rock mass strength.

Aug 1, 2013

By BRIAN HITCHON

Calcium, magnesium, bromide and iodide extraction from formation waters for use as industrial minerals has occurred in several countries, but not yet in Canada. Potential commercial brine fields exist in th e Upper Devonian Beaverhill Lake Formation of so uthern Alberta, and the Middle Devonian Elk Point Subgroup of north-central Alberta, f rom which calcium, magnesium and bromide are potential products. Iodide contents in fo rmation waters f rom the Upper Cretaceous Belly River Formation and the Lower Cretaceous Viking and Bow Island fo rmations in central and southern Alberta are at the lower range limit of commercial iodide-bearing formation waters elsewhere in the world. Available information is insufficient 10 outline potentially commercial areas in Alberta, but such info rmation can be most easily obtained f rom test borings for shallow natural gas. Lithium is not now produced commercially f rom formation waters but its content should be monitored in view of f uture increased demand for this metal.

Jan 1, 1984

By Lihong

A series of Fe2O3-elimination experiments were conducted on feldspar samples from Tangshan Stone?powder Plant. These experimental methods include scrubbing desliming, flotation,rod milling and high gradient magnetic separation. Some technical factors of feldspar concentration and a new technological flow?sheet of ceramics raw material concentration were put forward.

May 1, 2003

"The Society for Mining, Metallurgy, and Exploration (SME) Inc. developed a guide of minimum standards for reporting exploration results, mineral resources, and mineral reserves for the purpose of informing the general public. The SME Guide has been adopted by the Society.History1. In 1988, at the request of members of the Society for Mining, Metallurgy, and Exploration (SME), Inc., the President of SME formed Working Party #79, Ore Reserve Definition, with the mission to develop guidelines for the public reporting of exploration results, resources, and reserves. A Subcommittee was appointed by the Working Party to draft these guidelines and submit recommendations to SME. The Subcommittee's recommendations were published by SME in the April 1991 issue of ""Mining Engineering"", and as a document entitled ""A Guide for Reporting Exploration Information, Resources, and Reserves"" (the SME Guide) in January 1992. Work continued on an ad-hoc basis until 1996, when Working Party #79 was renamed the SME Resources and Reserves Committee and became a standing committee.In 1994, the Council of Mining and Metallurgical Institutions (CMMI) started a concerted international effort to create a set of international definitions for reporting mineral resources and mineral reserves. An ad-hoc International Definitions Group was formed, with representatives from mining and metallurgical institutions from the United States (SME), Australia (AusIMM), Canada (CIM), the United Kingdom (IMM) and South Africa (SAIMM). A major breakthrough came on October 18, 1997 when the CMMI International Definitions Group met in Denver, Colorado and reached a provisional agreement (the Denver Accord) on definitions of mineral resources and mineral reserves. Concurrently, and since 1992, the United Nations Economic Commission for Europe (UN-ECE) was developing an international framework classification for mineral resources and mineral reserves. Starting in October 1998, joint meetings were held in Geneva between the CMMI International Definitions Group and the UN-ECE Task Force, resulting in agreement to incorporate the CMMI definitions into the UN framework classification."

Jan 1, 2003

By S. Castro

Hydrolysis of metallic ions depends on pH and the products of hydrolysis either activate flotation or can lead to inadvertent activation of gangue particles, but can also depress flotation of valuable components. One of the most recently studied topics is the use of seawater in flotation. Seawater is a concentrated NaCl solution (about 0.6 mol/L) that also contains considerable amount of Mg2+ and Ca2+ ions. The hydrolysis products of Mg2+ strongly depress flotation of molybdenite over the pH ranges over which they form in the process water. This effect can be eliminated by removal of hydrolysing ions from the process water or by carrying out the flotation at the pH over which such a hydrolysis can be avoided. The former can be exemplified by prior precipitation of the harmful hydrolysing ions as, for example, in the University of Concepcion Patent. The latter can be exemplified by the use of metabisulfite to depress pyrite in the flotation of Cu-Mo sulfide ores in seawater, the process that is carried out at much lower pH, which avoids formation of Mg2+ hydrolysis products.

Jan 1, 2017

By Brian K. Ayres

Inco Limited, Ontario Division is currently in the process of decommissioning the Whistle Mine site located near Sudbury, Ontario, Canada. The most significant component of site decommissioning involved relocating approximately 6.4 million tonnes of acid-generating waste rock to the open pit from two adjacent stockpiles. An engineered cover system was designed for the backfilled pit to reduce the long-term production of acid rock drainage. Geochemical modelling was conducted to assess the effectiveness of various cover options on the longterm water quality of the backfilled pit. Results obtained from performance monitoring of cover system field trials at the site and estimated full-scale construction costs were used to select an appropriate material for the cover system barrier layer. The two-dimensional soil-atmosphere model VADOSE/W was used to develop a calibrated model of covered waste rock based on field data obtained from the cover trials, which was subsequently used to predict net percolation and oxygen ingress through various cover system alternatives for site-specific climate conditions. Erosion and landform evolution numerical modelling was completed to assist in designing the runoff management system and final landform for the pit cover system. The potential impact of various physical, chemical and biological processes on the sustainable performance of the pit cover system was also considered in the design process. This paper provides an overview of the design and construction of the backfilled pit cover system.

Apr 1, 2005

By I. Takahashi

Recently, electronic devices have become smaller for some kinds of electronic devices, thermal dissipation and electrical conductivity of conventional Fe based alloy becomes insufficient. We selected the Cu-Fe based alloy CDA19400 and optimized the wire manufacturing process. Precipitates during aging treatment were observed by TEM. The size and distribution of the precipitates varied according to solution treatment temperature. With solution treatment at 950°C, the precipitates of y-Fe as fine as 10 nm were distributed dense in the copper matrix with coherency. For the solution treatment at 750°C, y-Fe of approximately 200 nm was observed. Comparing heat resistance of drawn wires, the material at 950°C treatment was superior. Electrical conductivity decreased from 63% IACS upon aging to 29% IACS by drawing. It is considered as particular phenomena for wires where materials are drawn with high reduction ratio. By the optimized manufacturing process, we successfully developed a new wire that has superior in strength, thermal conductivity, electrical conductivity, heat resistance and repeated bendability.

Jan 1, 2007

By Jeff Bird, Xijia Wu, Prakash C. Patnaik

"Prognosis and health management (PHM) is an evolving suite of technologies intended for application to the life cycle management (LCM) of mission/safety critical systems, with anticipated results, which will: - Reduce life cycle cost - Enhance operational safety and readiness - Assist in maintenance decision-making - Enable autonomic logistics While it is emphasized in the United States that future multi-mission fighter aircraft such as Joint Strike Fighter (JSF) must have PHM capabilities, Canadian initiatives also recognize the need to implement such schemes for future and legacy military and civil aerospace systems. With respect to four major technology areas of PHM, i.e., i) advanced sensors, ii) data analysis and fusion, iii) life consumption evaluation, and iv) predictions with reliability/risk assessment, there has been advanced technologies developed by NRC and others within Canada: - Aircraft/engine instrumentation and airborne data recording systems - Signal analysis and data fusion - On-line engine health monitoring - Physics based models for engine material failure modes and life prediction - Autonomic crack growth analysis for damage tolerance of engine components - Mission severity analysis algorithm - Probability, reliability and risk assessment This presentation reviews the above technologies in relevance to PHM, emphasizes the need to have physics based models and outlines the future R&D needs for integration and implementation of these technologies suitable for the advanced and legacy aircraft."

Jan 1, 2004

By E. G. Langille

"The Premier mine; owned by Silbak Premier Mines; Limited; is 14 miles from Stewart at the head of Portland canal. Development of the property began in 1918; and since chat time a very large amount of gold and silver as well as some lead and copper have been produced from the mine.The area in the vicinity of the mine is underlain by greenstones tuffs, and sediments of Mesozoic age, belonging to the Bear River formation of the Hazelton group. These rocks are intruded by a stock 2 miles in diameter, composed of orthoclase porphyry and called the Premier porphyry. It sends numerous sill-like and dyke-like tongues into the Bear River formation, and is intruded in turn by a granodiorite outlier of the Coast Range batholith. The orebodies occupy fractures and fracture or shear zones. Primary ore consists chiefly of pyrite, galena, and sphalerite, with some chalcopyrite. The upper 300 feet, or locally 600 feet, contained presumably secondary silver minerals."

Jan 1, 1954

By F. Romero

In the last four years, Compañia Minera Doña Ines de Collahuasi has been working in the application of advanced multivariate statistical techniques for the improvement of the metallurgical processes. In this paper the main conclusions for the application of multivariable analysis to the EW process are presented; including the identification of (target) process patterns according to throughput and quality criteria. Based on the process patterns, process variables hierarchies were identified by selecting the most influential ones, as well as to identify and isolate the root causes of pattern deviations and sub-standard operating conditions, cause-effect relationships were established, leading to the definition of process policies and controls to give early corrections to potential failures. The analysis was focused on cathode quality, specifically in its sulfur content, using an empirical model based on those variables that from a phenomenological and statistical stand point appeared to be the most influencing ones.

Jan 1, 2007

By K. Soldenhoff

Mantra Resources Ltd is developing the Mkuju River project is southern Tanzania. The uranium deposit, hosted in ?Karoo? sandstone, is surface outcropping with the majority of uranium mineralisation occurring in the finer clay component of the ore. A flowsheet, consisting of ore beneficiation, acid leaching, RIP uranium recovery and direct precipitation of the uranium product, was developed and successfully demonstrated in continuous mini-plant operations at ANSTO. The selected flowsheet overcomes the difficult slurry rheology, arising from the clay component of the ore, by eliminating the need for a CCD plant. The RIP process was found to contribute to a high uranium extraction, by eliminating ?preg-robbing?, at a relatively low acid addition in leach, with the potential to eliminate ferric ion and oxidant additions.

Aug 1, 2010

By F. E. P. PEARSON

Sandstone quarried from an island in Lake Winnipeg is barged 130 km to a processing plant at Selkirk on the Red River. The stone is white, poorly consolidated, and consists of rounded quartz grains of high natural purity. It is an important supplier of silica in Western Canada for glass, fiberglass, foundry and other industrial uses.

Jan 1, 1984

By A. Sadough vanini A. Kami

In this paper, effects of different ageing treatments on the mechanical properties, microstructure and formability of 7075 aluminum alloy have been studied. Forming limit diagrams of the alloy have been obtained for four ageing conditions including T6, OA1, OA2 and O. For this purpose, combination of uniaxial tensile tests and the Erichsen cupping tests with different sizes and shapes of sheet specimens have been performed after each ageing treatment. The highest formability and the lowest formability have been observed at samples with O and T6 ageing treatments, respectively. Also, investigation of precipitated microstructures showed that the size of precipitation particles has a significant effect on the formability of the alloy. Formability improves with coarsening of precipitation particles.

Oct 1, 2011

"In 2008, the Committee for Mineral Reserves and International Reporting Standards (CRIRSCO) and the Russian State Commission on Mineral Reserves (GKZ) entered into an agreement leading towards harmonization of Russian and international minerals reporting systems. The purpose of the protocol is to define an agreed method by which mineral resources and reserves, reported by companies in Russia according to the current Russian classification system, can be expressed in terms that are comparable to the CRIRSCO reporting codes in Russia and elsewhere."

Jan 1, 2003

By S. Demetrio

China has a traditional segment of Copper Smelters with its own Chinese technology, typically small in size from 20.000 to 50.000 tCu/a, and they are responsible for the processing and production of more than 600,000 tonnes of blister copper per year. For occidental experts, like one of the authors, it is not so easy to believe that they are profitable, because the size and the use of old Blast Furnaces, but they are with simple and effective production lines. The authors are convinced that China has a good alternative to improve theses old copper production lines with small innovative changes in its process arrangement, jumping to higher level technology, more efficient in production, productivity and cost, assuring copper as a raw material for the country and its high speed development. The key to improve that the traditional Chinese Copper Smelter is white metal as an extra raw material as a first step doubling the copper production from raw materials and the complete replacement of concentrates by white metal (WM) in a second step increasing it four times or more as the final goal. It is not so difficult nor expensive to make it happen, but there are a couple of questions for implementing this innovation in the copper smelter industry: 1 - Will the old fashioned mentality be open to this new direction for China being the biggest copper consumer on one side, and the biggest copper Primary Producers on the other hand? and 2 - Will they be open to follow this "win-win" strategic way for both ends of the copper market? We don't know if anybody will take up the challenge to improve it but our responsibility as a consulting expert and a university professor is to put the alternative on table for others to decide whether to implement it.

Jan 1, 2007

By Z. Manafi

Bioleaching of a copper sulfide ore containing "activated pyrite", using a mixed culture of mesophilic bacteria, was studied. This type of copper ore had been found unsuitable for flotation because it produces a concentrate containing relatively high iron concentrations and, therefore, a low copper grade. Microscopic observations showed that pyrite particles had been activated by the formation of a thin film of chalcocite. Hence, a bioleaching process was considered as an alternative to treat this ore. Following shake flask and acid consumption tests, column tests of the crushed ore (75% -12.5 mm) were initiated and the effects of culture medium, agglomeration, and irrigation type on copper recovery were studied. The results showed that all the columns containing bacteria had copper recoveries around 90% compared to the abiotic control column with a recovery of 50%. It was concluded that bioleaching could be successfully utilized to process copper ores containing activated pyrite.

Jan 1, 2007

By Louis Tellier

SIDBEC commenced detailed planning of major capital expenditures to install integrated steelmaking facilities in 1969. Today, less than IO years later, SIDBEC and its subsidiaries have completed major mining, concentrating, pelletizing, direct reduction ? electric furnace steelmaking and continuous casting plants. The total cost of these projects was almost 1 billion dollars. The philosophy behind the project planning and the evolution of management control are explained. These extensive projects were undertaken during a period of exceptional inflation and a disturbed labour climate, but were nevertheless completed with only modest overruns, with good control of timetables and with exceptionally good start-up performance. Project planning, relations with consulting engineers, introduction of new technology, purchasing and field management and cost control are discussed.

Jan 1, 1979

By L. Contretras

This study has as an objective to analyze and to propose actions to improve the quantity and quality of the graduate education in the area of mining industry, specifically of mining engineers, metallurgists, geologists, to satisfy the expectations of professionals in the mining industry. Included are an analysis of the present scenario and the future demands in countries like Chile and proposed plans for the Establishment of Educational Initiatives, country policies and market forecast, vis-a-vis the experience of Australia, South Africa, United Kingdom, Canada and the United States of America.

Jan 1, 2007