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The effect of temperature, time and SO2 concentration in the atmosphate have been studied for a complex Pb-Zn concentrate, which contained four sulphides and some organic material, in order to determine optimum roasting conditions. Under static roasting conditions virtually complete sulphation was achieved after roasting at 650¦C.2 hours in 10% SO2 in air. Both zinc ferrite and zinc silicate were observed to form early in the roasting, but continued exposure to SO2 -containing gases caused decomposition of these as the roasting time increased. Water and acid solubilities of iron, silica, calcium, magnesium and aluminium in the calcine were determined, as a function of roasting time, temperature and atmosphere composition.

Jan 1, 1970

By Lewis IE

Copper-lead dross is a by-product of the refining of lead bullion produced by the Imper- ial Smelting Process. This dross contains some 27 percent copper, 50 percent lead, four percent zinc and one percent sulphur. An ammonium carb- onate leach at atmospheric temperature and pressure removed the copper from the dross while the lead zinc and precious metals remained in the leach residue for return to the smelter. The leach solution containing the copper was then purified by liquid-liquid ion exchange using LIX64N in a kerosene diluent. ("LIX" is the registered trade mark of a range of hydroxy oximes marketed by General Mills Inc.) The pilot plant had a capacity of 0.7 kg/h of CuSO4,5H20 and was operated for some fifty days on a two shift basis. Copper sulphate of excellent purity was produced, and the results obtained indicated that a copper recovery of ninety percent from the dross could be expected from a commercial installation.

Jan 1, 1975

By Morrison RD, Simmons CJ

A bewildering array of process control instrumentation is currently available for mineral processing plants. For sequencing control, special purpose microprocessors or the process control computer can be used. Where continuous control is required, then the choice is between pneumatic controllers, electronic controllers, shared display micro- processor systems and direct digital control. The benefits of each system are discussed and the advantages of using direct digital control in mineral processing plants are outlined. The factors which need to be considered when selecting control systems for new plants are listed. Instrumentation systems designed by Fluor Australia are used as case studies to illustrate the selection process. For established plants, conversion to direct digital can be advantageous, and case studies are given. However, replacement of existing systems requires justification based on a productivity improvement which will allow the control equipment to be paid for within a specific time period. Productivity improve- ments maybe assessed in terms of increased

Jan 1, 1978

There are two main areas of application of geology in quarrying: (i) In regional planning for industrial mineral requirements.(ii) In direct quarry management. The regional planning requirement has recently become more evident because of greatly increased land demand conflicts around cities. The direct quarry involvement is a reflection of both the economy and the greatly increased sophistication of the quarry industry. Here, professional planning and development expertise by a geologist is required, to ensure continued supply of raw materials at the best price to the consumer with sufficient profit to the producer. Today, geological insurance safeguards capital investment in plant and assures economical development plans.

Jan 1, 1978

By Robson L. C

The developing countries whether they be in Africa, Asia or the Pacific, are a potentially vast market for the technologies of the more developed countries.Conducting business in the less developed countries however requires a keen understanding of their culture. A keystone of the culture of the Pacific Island Nations is kinship with the land. Without an appreciation of the implications of the land rights debate, a business venture into these countries is likely to be delayed or even doomed to failure.The European heritage, with its notions of private ownership of land, have frequently been a stumbling block to a proper understanding of the concepts of customary lands. According to our laws, ownership of land confers a number of definite rights: principally the right to use the land, the right to exclude others from its use, the right to transfer it and the right to receivF income from the property independent of use.

Jan 1, 1990

Samples weighing 0·5 g are fused with sodium hydrogen sulphate, leached with 5 ml. of 4 M nitric acid and diluted to 10 ml. with water. An aliquot of the clear solution is boiled with concentrated nitric acid and then 2 ml. of a phosphotungstate solution are added. After dilution to 10 ml. with water, the solution is heated in a boiling water-bath for not less than 10 min. When cold, the solution is extracted with 2 ml. of iso-amyl alcohol and the yellow phosphotungstovanadate complex is compared with a standard series. Concentrations down to 4 p.p.m. may be analysed at a rate of 100 samples per man-day of 8 hr.

Jan 1, 1971

Reservoir Engineering has developed into an art. One phase of this art is forecasting the futi. perf ormance of oil and gas reservoirs for property valuations. A discussion of the necessity for oil property valuation isgiven. A brief 'discussion of the four most common methods is included and the engineering method is explained in more detail. As an example of oil property valuations, a producing oil lease in Shackelford County, Texas, USA is evaluated.' The recommendations and conclusions arrived at frun the results obtained are presented.

Jan 1, 1962

In 1985 a 2.5-tonne top blown rotary converter was installed in the silver refinery at Cominco's Trail Operation to carry out the final cupellation of burndown metal to Dore metal. The furnace is fired with an oxygen-natural gas lance which is capable of achieving a variety of furnace conditions, varying from reducing to highly oxidizing. Reaction rates are about 4 times greater than using conventional cupel furnaces. The faster reaction rates improve productivity and reduce in-process precious metal tie-up. The furnace is also used to reduce litharge slag for bismuth recovery.

Jan 1, 1989

By Madgwick J

A novel method for determining viable cells of the mineral leaching bacterium Thiobacillus ferrooxidans has been developed. The cells were collected on 0.45/Lm cellulose acetate filters, washed with artificial minewater, and incubated in the presence of ferrous ion at pH3 in an atmosphere containing radioactive (14C) carbon dioxide. Colonies of bacterial growth were detected by the image formed on X-ray photographic paper (autoradiography). The method was compared with three conventional techniques and shown to detect three orders of magnitude more cells in cultures of Thiobacillus ferrooxidans in the late exponential phase of growth.

Jan 1, 1987

By Gelding P. W, van Herk H

The Cattlegrid copper orebody is a concealed thin, tabular sheet localised near an unconformity between two sub- horizontal Precambrian sandstone units. It extends over an area of 1,000 m by 500 m within a wider area of mineral- isation. The ore consists of complex sulphides and is neither massive nor disseminated. It consists mainly of irregular fillings in pore space developed between clasts in sandstone breccias, in fault zones and joints and along stratification planes. Its habit is unique amongst Australian base metal ore bodies. During the pre-development period ore was outlined by percussion holes but in studies leading to investment decisions ore reserves were manually calculated from intercepts and assay results of cores from diamond drill holes. The methods used for estimating reserves in the pre-production and production periods are described and evaluated by comparing mine production during the first five ore production years with the forecasts made.

Jan 1, 1979

By Manula C. B

The total systems model for underground oal mining planning and design is a set of omputer programs which encompasses a realis- ic reproduction of the interaction between he geological, environmental, equipment, meth- ds and the health and safety aspects of the ining plan. The total system includes nine ajor subsystems - Geology and Reserves, Meth- ne Generator, Roof Support, Subsidence, Pro- uction, Rail Haulage, Cost, Water Generator, nd Ventilation. The subsystems themselves re divided into two categories based on the requency with which they are executed. Event riented Subsystems are executed either inde- endently, or at discrete intervals when cer- tain specific events occur. Dynamic subsystems 'unction interactively during the production :ycle. They transfer data to or request data `rom event oriented subsystems only when spe- ific events occur. Three specific areas for iodel application are in the measurement of system performance, the development of the '_ nterrelationships of the components of deep Wining process and the evaluation of new and Lnnovative mining technology.

Jan 1, 1977

By Sandy W

This paper examines the effects of a significant number of plant alterations and modifications to the lead flotation circuit during the past five years. Metallurgical effort is directed largely at the flotation performance of middling streams and current strategies are discussed. The automatic control of cell destination and collector additions are outlined in the latter section of the paper, along with a description of control hardware in current use.

Jan 1, 1983

By W J. Rankin

A study of refined metallic copper and nickel production was carried out using Life Cycle Assessment methodology to estimate the life cycle emissions of greenhouse and acid rain gases for these metals using data derived from the literature. Various processing routes were investigated which included a pyrometallurgical and a hydrometallurgical route for each metal. The effect of a number of process variables, namely ore grade, fuel type for electricity generation and efficiency of generation were also examined in the study. The results of the study, expressed in terms of total (or full cycle) energy consumption, Global Warming Potential (GWP) and Acidification Potential (AP), showed that the hydrometallurgical processes involving solvent extraction and electrowinning had higher energy consumptions and GWPs than the pyrometallurgical processes for both metals. Nickel metal production was shown to be several-fold more energy intensive than copper metal production. The significant effect that falling ore grades have on attempts to meet greenhouse emission targets was also highlighted in the study.

Jan 1, 2000

By Moorrees C

The end uses of magnesia are determined by both its chemical and its physical proper- ties. There is seen to be an increasing need for products of high chemical purity. Prod- ucts containing 90-95 per cent MgO can be routinely produced by physical beneficiation and calcination of most magnesite ores, the dominant source of magnesia. However, pro- duction of grades containing more than 98 per cent MgO with low impurity levels is not readily achieved physically. Such products can only be readily produced by chemical processing techniques. This presentation outlines the types of impurities present in magnesite deposits and the general concepts that are involved in chemically upgrading them. Of the potential leachants, only hydrochloric acid and aqueous carbon dioxide appear to be commercially attractive.

Jan 1, 1987

By Thompson J

A programme of testing and evaluation has been in progress at Isa Mine for the last four years with the objectives of rationalising ground support practices, improving installation quality and increasing productivity of ground support functions.Numerous innovations have been successfully implemented. These include the introduction of swellex rockbolts as the major form of temporary support, the use of splitset rockbolts as the primary means of support for the hangingwalls of cut and fill stopes and the introduction of dowels with pumped cement for general long term support.The installation of swellex bolts has been successfully mechanised throughout the mine using Tamrock automatic rockbolters and Atlas Copco BUK 11R drilling rigs modified for this purpose.

Jan 1, 1985

Paste Thickening of Tailings at the Clermont Coal Preparation Plant

Sep 13, 2010

By Newell R

The influence of layering on the rate of heat transfer through a packed bed consisting of particles of two different sizes and heat capacities has been determined by measuring the heat front velocity through beds of quartzite particles and iron ore pellets. The heat front velocity through the layered beds was less than that through a bed consisting of a random mixture of the par- ticles. This is due to the formation of an interface in which the smaller pellets in one layer penetrate into the layer of quartzite Below.

Jan 1, 1987

By J Wiklund

The impact of non-ferrous smelters on their local surroundings is well monitored and guarded by various actors: the owners looking for profitability, the villagers looking for employment, the consumers asking for ever cheaper products and services, the government collecting taxes and all cherishing the environmental impact. Recent challenges facing the industry are various new doomsday projections: that we will be running out of base metals, that the ground we dwell on will be contaminated by the use of products. Smelters, such as BolidenÆs R÷nnskSr Smelter have a long history of increasing non-ferrous resources by recycling. It is shown that extraction and recycling of metals together with energy recovery can be integrated in a modern, profitable and clean smelter. Examples of efforts to further improve the business will be discussed such as flowsheet rationalisation, environmental investments, new feed from recycling and energy utilisation.

Jan 1, 2000

Porgera is located in the Central Highlands of Papua New Guinea. Porgera Joint Venture treats a high grade epithennal gold deposit. Most of the gold occurs as submicroscopic particles in a sulphide matrix although there is some quite coarse free gold. Anticipated gold production is 900 000 oz per year for the first six years of operation.Stage I of the treatment plant consisted of a concentrator and leach/CIP Circuit. It was commissioned in August 1990. Design throughput was 1500 tpd with an anticipated gold recovery of 60 per cent. Throughput achieved was actually 1850 tpd with an average gold recovery of 69 per cent. CIP tails were accumulated in a pond awaiting retreatment by pressure oxidation.

Jan 1, 1992

The production of copper by the Outokumpu direct blister process commenced in July 1988. The problems and incidents encountered in commissioning the main smelter equipment are outlined. Early difficulties were encountered in process control, hot metal handling, dust buildup in the off gas handling equipment, waste heat boiler tube failures, foam over of hot metal into the waste heat boiler and failure of ancilliary equipment.

Jan 1, 1989