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By Russell R. McLellan

The Tertiary channel gravel deposits in northern California were selected Or detailed investigation by the U. S. Bureau of Mines as part of a national program to locate potential sources of gold that might be developed rapidly by large-scale mining operations. Five bureau research centers representing mining and metallurgy subsystems coordinated their efforts in a team operation to identify and investigate possible solutions to the problem area, that long have discouraged the resumption of large-scale mining in the deposits. This report summarizes the individual investigations, conclusions and recommendations conducted and prepared by all mining subsystems research groups after the completion of two years of field work at the deposits on San Juan Ridge in Nevada County, California. The studies indicate that modern mining technology can cope with the environmental problems that closed the immense hydraulic mines in 1,884. however, they also indicate that mining can be conducted with only marginal profits its unless the price of gold remains substantially above $70 per ounce or unless sufficient by-products can be recovered and sold to place the average value per cubic yard of gravel into a positive commercial range. The by-product potential of the Tertiary gravels remains to be investigated in more detail.

Jan 1, 2012

By Peter C. Jones

Owing to the inadequacy of the ore transport system at Cassiar in the late 1960's, a new facility was required. This paper traces the various alternatives considered and gives a description of the tram line as installed. The problems encountered, changes made and future modifications are discussed in detail, together with the effects these have on maintenance and operations.

Jan 1, 1978

By David Runnels

In September 1970, the Quebec Cartier Mining Company, started development of the Mount; Fright iron ore mine. The estimated ore reserve is in excess of 1,000,000,000 long tons with an average grade of 31.5% Fe. The run of mine ore is crushed, ground and concentrated to a product having 66% Fe and 5% silica at an annual concentrate production rate of 18.4 million long tons. The daily production rate of over 50,000 long tons of concentrate necessitates a daily mine output of approximately 250,000 long tons of material of which 50% is waste. The mine is located in the Province of Quebec, close to the Labrador border approximately 600 miles north-east of Montreal. The development of the mine necessitated the construction of an all electric one thousand housing unit townsite along with associated services such as a shopping center, swimming pool, arena, school, etc... A one-hundred mile long, 315 K.V. Dower line was built between the mine site and the Hydro-Quebec 735 K.V. existing power line between Churchill Falls and the Montreal area. The construction near the mine of a beneficiation plant was necessary to upgrade the 31.5% iron ore to a marketable product of 66% iron.

Jan 1, 1977

By A Jakowetz

OxianaÆs Sepon Copper Operation (part of the combined Sepon Gold and Copper Operation) is located in Savannaket Province, in southern central Lao PDR. The site is relatively remote, being some five hours inland from the Laos/Thailand border crossing on the Mekong River. The copper processing plant was designed to treat 1.3 Mtpa ROM ore to produce 60 000 tpa of copper cathode. Commissioning of the processing plant was completed in mid March 2005 with ramp up completed in January 2006 with 5260 tonnes of cathode harvested in this month. The focus of this paper is on SeponÆs unique grinding circuit. The entire grinding circuit is operated at highly acidic conditions, adding a number of different operational issues over and above those normally associated with grinding circuits. It became evident early in the ramp up, that reaching design mill throughput of 170 dry tonnes per hour with the original design would be challenging, coupled with the realisation that ceramic grinding media consumption had been underestimated. In order to lift the overall throughput of the processing plant, a significant continuous improvement process has been implemented within the grinding circuit to lift this key unitÆs production capacity. This presentation will focus on the key areas that have been addressed in the 12 month ramp up period and highlight areas for future work. Results to date have shown this improvement process to be very successful, with throughput rates in excess of 200 tph regularly achieved.

Jan 1, 2006

By S. H. Lorain

The Minah silver-lead mine in the Wickes district, Jefferson County, Mont., produced substantial quantities of silver-lead ores in the 1890's. The mine has been abandoned since the "silver panic" of the early 1900's. As a part of the Bureau of Mines: program to develop new sources of lead to overcome the growing shortages of that metal, a development project was started at the Minh mine in April 1946 and continued until June 1947, during which 5,600 feet of angledozer trenching and. 1,093 feet of core drilling were completed on the main vein and nearby parallel veins: As a result of this work, interest in the property was stimulated and private operators are now engaged in reopening the mine. This report discusses the past history, geologic setting, and the recent and early operations of the mine.

Jan 1, 1948

By P. C. Benedict

"The Island Mountain mine is at the southeast end of Island mountain; across Jack of Clubs lake from the Cariboo Gold Quartz mine.; The orebodies consist of quartz veins and pyritic replacement deposits in limestone. To December 31; 1944; there has been mined 296; 273 tons of quartz-vein ore averaging about 0.34 oz. gold a ton; and 101; 002 tons of sulphide ore averaging about 0.83 oz. gold a ton; a total of 397; 275 tons averaging 0.46 oz. From this; 175; 985 fine oz. of gold and about 26; 450 fine oz. of silver were recovered; having a value of $6; 510; 521.More than 95 per cent of the production has come from a band 500 feet wide along the contact of the Rainbow and overlying Baker members and extending about 100 feet into the latter. Evidence that the Rainbow belongs stratigraphically above the Baker is presented later in this paper. Both members are most variable lithologically, and individual beds and whole series of beds pinch out in short distances. In part, at least, this is due to squeezing out incidentally to intense folding. No section can be claimed with assurance to be really representative. However, both memb.ers are composed predominantly of quartzitic rocks. Both contain argillaceous quartzite, argillite, limy quartzite, limy argillite, limestone (marble), and minor amounts of highly ankeritized rocks believed to be igneous sills possibly originally approaching diorite in composition."

Jan 1, 1954

By S. H. Lau

Rapid 3D characterization of multiphase mineral particles in a variety of mineral processing applications is described, including: mineral liberation analysis, grain size, mineral exposure analysis, particle damage, and pore network structure for fluid flow simulation in heap leaching. While micro X-ray computed tomography systems (microCTs) have been used for many years, industrial adoption is limited due to a variety of reasons, including insufficient resolution, the general lack of imaging contrast to differentiate different mineral phases within a multiphase mineral particle and the lack of automated 3D mineral processing software. For example, resolution with industrial CTs and desktop microCT is of the order of tens of microns to a few microns at best, depending on specimen size and CT configuration. We describe a novel lab-based X-ray microscope, XRM, which overcomes these resolution and contrast limitations, notably as the industry is going towards finer grains and more complex ore bodies. Using lens-based optics and detectors (similar to its XRM counterpart in synchrotron beam lines), resolution of the lab based system is in the submicron range with contrast better than conventional microCTs. Hence, visualization, differentiation and segmentation of most mineral phases of interest to the industry are now feasible. Coupling these high resolution and high contrast tomography images with a suite of customized 3D segmentation algorithms and analysis software, applications in mineral liberation analysis for process control, particle damage assessment and other mineral processing applications can be achieved. This non invasive 3D technique which requires relatively little sample preparation is currently being considered for coal, industrial minerals, and base/precious metal ores, complementing existing microscopy techniques such as QEMSCAN and MLA for a variety of applications

Sep 1, 2012

By B. R. Richards, B. G. W. Robinson

"This paper shows how metal values can be profitably won from a comparatively small and remotely located but high-grade orebody. To do so is not uractical for a large mining company, with its necessarily high overhead of services and organization essential to a large producer.To evaluate, develop and profitably exploit a limited but defined ore deposit becomes only a problem of determining the dollars required to win the dollars available. This paper will record how this was carried out during 1965 and at the same time describe the history, development and production plant of this property."

Jan 1, 1966

By J. P. Dai

The Fankou Mine in Guangdong province, China, processes a polymetallic ore containing averagely 4.2% Pb, 8.5% Zn, and 90 g/t Ag. The main metal minerals including sphalerite, galena and pyrite are very finely disseminated and unevenly occurred in the ore, making it difficult to liberate them from each other. This paper presents the processing technology of the Fankou plant and the characteristic features of the novel technology applied.

Jan 1, 2014

By A H. Bagherieh, S Mesroghli, H Jorjani, S Chehreh Chelgani

The rare earth elements (REEs) assay and recovery in leaching processes is being determined using expensive analytical methods, ICP-AES, and ICP-MS. This paper presents a neural network model to predict the effects of operational variables on the lanthanum, cerium, yttrium, neodymium recovery in the leaching of apatite concentrate. The effects of leaching times: ten to 40 min, pulp densities: 30 to 50 per cent, acid concentrations: 20 to 60 per cent and agitation rates: 100 to 200 rpm were investigated and optimised on REEs recovery in laboratory at a leaching temperature of 60¦C. The obtained data, on the laboratory optimisation process were used for training and testing of a neural network. A feed-forward artificial neural network with 4-5-5-1 arrangement, was capable of estimating the REEs leaching recovery. Neural network predicted values were in good agreement with the experimental results. The correlations of R = 1 in training stages, and R =  0.971, 0.952, 0.985 and 0.98 in testing stages were results for Ce, Nd, La and Y recovery predictions respectively and that theses values are considerably acceptable. It was shown that the proposed neural network model accurately reproduces all the effects of operation variables, and can be used in the simulation of a REEs leaching plant.

Jan 1, 2008

By A. Kontopoulos

The extraction of nickel and cobalt from low-grade greek laterites by sulfuric acid leaching has been studied. Batch and continuous mini-plant atmospheric leaching as well as pressure leaching techniques were employed. Atmospheric leaching at temperatures as high as 95 OC generally resulted in low Ni extractions (up to 82%), high acid consumption (650-850 kg/t ore or 80-100 kg/kg Ni) and high Fe co-dissolution (30%). Pressure leaching at 260 OC increased Ni extraction to over 98%, with minimal Fe co-dissolution (2.5%); acid consumption was 300 kg/t ore (31 kg/kg Ni). Detailed experimental results and conceptual flow sheets for atmospheric and pressure leaching are presented.

Jan 1, 1991

By J. A. C. Ross

Introduction To enlighten those who may be wondering where anyone could find sufficient data to write a paper on underground concrete work, the author would like to explain that, at Copper Mountain, we have found it necessary to line numerous headings with a layer of concrete in order to keep them in a safe and serviceable condition. The majority of these headings are scram drifts and ore-pass raises. This paper will therefore deal, in the main, with the methods of and reasons for placing concrete in these headings. During recent years, radical changes have been made in the methods of mining ore at the Copper Mountain mine. After considerable experimenting, a mining system has been developed making use of diamond drills for primary breaking and transfering such broken ore through scram drifts with slusher hoists. With the advent of scram drifts, it soon became apparent that some substantial means of reinforcement and protection for the scram drifts themselves would be necessary. Since the orebodies in this mine are cut by numerous dykes or faults, and often both, it was anticipated that some means of support would be required where headings necessarily passed through these incompetent zones. Further, as experience was gained, scram drifts were driven into pillars and in close proximity to old workings so as to recover the maximum amount of ore. In such places, the ground is often severely fractured, either as a result of previous mining or from the effect of excessive rock pressures.

Jan 1, 1950

By Batric Pesic

A hydrometallurgical process for recovery of Zn and Mn from Bunker Hill Water Treatment Plant sludge was developed. The process is unique because it treats an unusual combination of metals, Zn and Mn. Another non-standard feature of the process is that leaching takes place with ~S04 in the presence of a reductant (SO2). Zn and Mn are recovered simultaneously by electrowinning, Zn on a cathode and Mn on an anode, as MnO2 The major purpose of the process is to detoxify the sludge by removing toxic heavy metals. The recovered metal values could be marketed to offset the overall costs of water and sludge processing. This work is presented in two separate parts, 1. Leaching and Solution Purification, and II. Electrowinning. This paper covers only the first part of the hydrometallurgical process: Leaching and Solution Purification. Initially, the paper briefly discusses the history of the pollution problem at the Bunker Hill Superfund Site, the origin of heavy metals in the mine waters, and the development and use of the water treatment plant. The leaching of sludge was examined as a function of the following parameters: constant vs. initial pH, initial vs. delayed addition of SO2, temperature, and pulp density. It was found that leaching with H2SO4 at pH 2.0 for 15 minutes (at 60°C), followed by S02 addition for another 15 minutes, could completely dissolve Zn and Mn. Solution purifIcation was done in three stages. In the first stage iron was removed by adjustment of pH (to pH 5.0) and oxidation offerrous to ferric iron (with H2O2). In the second stage, Cu and Cd were removed by Zn dust cementation. Finally, Co and Ni were precipitated with the organic reagents 1-2 nitroso-naphthol and nitroso, respectively. Electrowinning of Zn and Mn is discussed separately in Part II of this paper.

Jan 1, 1996

By J. Basi, D. F. Rucker

"A review of historic operating practices of the heap leach pads at the Los Filos Mine, Mexico, revealed periods of restricted cyanide addition, reduced leach time, and insufficient irrigation flow. These issues all led to the buildup of partially leached recoverable gold inventory within the leach pads. Drawing down this inventory represented an opportunity to bring value forward. This paper outlines the strategic initiatives which were implemented as efforts to accelerate the inventory drawdown, including geophysical mapping and pressure injection.INTRODUCTION Los Filos is a heap-leach operation located in the Guerrero gold belt in southern Mexico. Operational and hydraulic challenges at the Los Filos Mine have led to a buildup of gold in inventory within the leach pads. Operationally, periods of restricted reagent addition, reduced leach time, and insufficient irrigation flow have compounded over the last eight years, and resulted in significant inventory growth. Hydraulically, the leach pad has issues with low permeability and solution channeling due to the fines and clay content of the ore. The leach pad is storing high-grade pregnant leach solution (PLS) as perched aquifers above areas that are compacted and difficult to drain. These operational and hydraulic challenges made it particularly difficult to spatially predict the precise locations of the inventory build-up. Fortunately, the challenges at Los Filos are not unique to the mine, and others have taken steps elsewhere to reduce metal inventory through a program that targets areas for inventory drawdown. For example, Ghorbani et al. (2016) noted that a method of injecting barren reagent solutions, applied directly to specific areas of a leach pad to reduce inventory, was presented by Wan and Brierley (1997) and Wan (1997). Seal (2004; 2007), Seal and Jung (2005), and Seal et al. (2012) have put the injection methodology into practice in Nevada and Colorado gold mines with a technology called Hydro-Jex®. The goal of Hydro-Jex has been to supply reagents at a high pressure over a short duration, followed by periodical low pressure rinse periods to remove leached metal and resupply fresh reagent to the ore."

Jan 1, 2017

By MacDonald AJ, Raffield MP

The South Deep massive orebody consists of 20 to 30 in of payable conglomerates ranging in dip from 11¦ to 20¦ and at depths of between 2400 in and 34(10 in. The mine design process selected a mining method with a proven record of application that could be adapted to overcome the inherent difficulties associated with the depth, thickness and structural influences of the South Deep orebody. A modified cut and fill mining method provides a concentrated and highly flexible method of extraction. An integrated destressing cut will enable the modification of the stress environment such that it is suitable for massive mining operations. The choice of backfill type and stoping width in the destressing cut ultimately determines the characteristics of the stress modification and, as such, is critical to the success of the cut and fill operation. This paper discusses the decision process undertaken to determine the optimum backfill type and stoping width combination in terms of, conditions in the destressing cut faces and in the massive mining environment. Numerical modelling has been extensively used to analyse arious scenarios to aid in the decision process.

Jan 1, 1998

By Torma A. E.

Biotechnological processes are considered to be cost effective especially for situations where the recovery of metals from 'Very large volumes containing trace metal concentrations (less than 10 ppm) is concerned. Microorganisms, alive or dead, or their products can be highly efficient and selective biosorbents for metal concentration. It is important that the metal bound to the biosorbent can be stripped by suitable agent(s) and regenerated for repeated use. The stripped solution should be concentrated enough to be introduced into the common metal recovery circuit. The industrial acceptance of biosorption processes is dictated by increased competitive advantage over other processes. This paper reviews the pertinent literature?, regroups the information, and points out future possibilities for the mineral and metal processing industries.

Jan 1, 1992

By S. Titkov

At present, Russia is engaged in processing, 3new plants of hard-to-process potash ores with increased content (up to 10 - 12%) of insoluble impurities (insoluble residue ? I.R.). This required additional research to improve the process of potash ores flotation. Based on the study of the effect of dispersive properties of frother and its flow rate on the efficiency of aliphatic amines with different length of the hydrocarbon radical (as sylvite collector) there was showed the possibility to apply high molecular amine with length of hydrocarbon radical C20 ? C26 by normal temperature of circulated plant salt solution (saturated solution KCl ? NaCl ? H2O). There was designed and tested in plant conditions the modified amine collector with the length of the hydrocarbon radical C16 - C26, improving flotation of Sylvite under normal temperature of circulating salt solutions at potash flotation plants. There was made the study of the influence of the hydrocarbon radical length of alkylmorpholine on the Halite flotation from intermediate products of sylvite recleaner flotation with different content of I.R. (silicate-carbonate slimes), at normal and elevated temperature of salt solution. On the basis of the application of modified alkylmorpholine for Halite flotation, there was developed the process of further beneficiation for the intermediate products of sylvite recleaner flotation from potash ores with increased content of insoluble impurities, which can eliminate the circulation of the intermediate products in the process flow sheet of sylvinite ore processing and increase the KCl recovery into the finished product. Keywords: flotation, potash, halite, alkylamine, alkylmorpholine

Sep 1, 2012

By T Sprague, D Pateman

"The Gosowong Gold Project is owned and operated by PT Nusa Halmahera Minerals (PT NHM), an Indonesian company 75 per cent owned by Newcrest. It is located on Halmahera Island, in the North Maluku Province of the Republic of Indonesia, approximately 2450 km north-east of the national capital, Jakarta (Newcrest, 2017).Kencana is one of two underground gold and silver mines at the Gosowong Operation where ground conditions vary from competent to very poor. Development headings occurring in poor rock mass conditions require high capacity ground support including long tendon cable bolts. Manual installation of cable bolts in these development headings has been a time consuming process due to borehole collapse, blockages requiring subsequent re-drilling and a minimum eight hour grout curing time interval. The installation of cable bolts including the setting, plating and tensioning can impact the critical path for development heading advance resulting in development cycle delays.A review was conducted by PT NHM on current industry practices for alternatives to manual cable bolting. PT NHM subsequently approached Minova to assist with the development and trialling of self drilling anchors (SDAs) installed using jumbos with a rapid setting pumpable resin, CARBOTHIXTM. A series of system development trials were conducted and a reliable bolting system was developed utilising the existing jumbo drilling fleet with minimal required modifications.The system developed was a ‘one pass’ bolting process to install and grout SDAs using a two component resin with a remote, mechanised system. Improvements achieved from the system include: eliminating hole closure issues and more immediate support in poor rock mass effectively reducing personnel exposure to poor ground conditions by removing the requirement to access the drive backs reducing grout set time with full installation times for 6 m SDAs averaging 25 min.The resin grouting system has now been successfully implemented to effectively manage areas of poor ground conditions and to accelerate advance rates in high priority headings.CITATION:Pateman, D and Sprague, T, 2017. Development and implementation of a long tendon bolting system utilising resin grouting technology, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 79–84 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 16, 2017

By P. Clifford

FIPR-sponsored research will playa critical role in enhancing the competitiveness of the Florida phosphate industry as ore grade declines and environmental restrictions tighten. FIPR's program seeks to improve surface mining and pipeline transportation while reducing the energy cost for pumping phosphate matrix. The development of a reliable on-line analyzer and a modern process control strategy will result in improved processing efficiency. Significant improvement in overall efficiency will also be realized as the industry adopts column flotation technology. Economic acidulation of high-Insol rock will allow the industry to adopt simplified flotation flowsheets thereby reducing operating costs. Various applications of phosphogypsum would save the industry millions of dollars in constructing and closing gypsum stacks.

Jan 1, 1998

By Sol Weller

The Fischer-Tropsch synthesis consists of the formation of long-chain hydrocarbons by passage of carbon monoxide-hydrogen mixtures over metal catalysts, usually based on iron, cobalt, nickel, or ruthenium, at temperatures in the range 180°-300° C., and at pressures of 1-15 atmospheres. Although the reaction has been known and studied for more than 20 years, the mechanism by which it occurs is still poorly understood. One approach to understanding is to consider the effect upon the course of the synthesis of variations in each of the important operating variables. Consideration of the experimental data pertaining to these variables may suggest an over-all picture describing the synthesis - a picture which, in turn, would have to be consistent with all the known facts. The first part of this paper will be concerned with such a consideration of operating variables; the second portion will discuss recent work pertaining to the role of metal carbides as intermediates in the synthesis.

Jan 1, 1949