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Titanium tetrachloride may be reduced to trichloride with hydrogen on a hot tungsten filament and other hot: surfaces. The effect of temperature, time and size of t.he filament on the rate of reaction has been studied. A laboratory unit for preparing a few pounds of trichloride at a time is described. The yield of trichloride is 2·2 - 2·4 gm/sq. cm. of hot surface/hour at 1,000°C. and the energy requirement 3'5-4 kWh/pound of trichloride produced.'INTRODUCTIONThe lower chlorides of titanium (titanium tri- and dichlorides) are amenable to electrolysis, being electrovalent in nature. Furthermore, relative to other oxygen-free titanium salts, they are easy to prepare in a pure state and their use has been investigated to prepare titanium. The experimentaJ work described in this paper deals with the preparation of titanium trichloride by reduction of titanium tetrachloride with hydrogen on hot surfaces.REDUCING AGENTS FOR TITANIUM TETRACHLORIDEThe free energy diagram (Fig. 1) for the formation of chlorides suggests that titanium' tetrachloride may be reduced to trichloride by various reducing agents such as aluminium, zinc, arsenic, antimony, tin, mercury, silver, hydrogen, sodium, potassium and magnesium. Ruff and Neumann (1923), Thorpe (1885) , Billy and Brasseur (1935) and Seurbert and Schmidt (1892) used various metals to reduce tetrachloride to trichloride and found that the yields were invariably low and the products difficult to separate.Besides the metallic reducing agents, hydrogen may also be used to reduce titanium tetrachloride to trichloride.Goerges and Stahler (1909) obtained a deposit of violet...

Jan 1, 1956

By D Stow, M Edmondson

Lemington coal mine is operating in an environmentally sensitive area in the Hunter Valley, NSW, Australia. Late in 1999 the southern pit was developed using a series of box cut blasts. After the initial development the area would have been free dug due to the soft, well-jointed nature of the deposit. However, it was decided to trial drill and blast to determine if shovel productivity could be improved to enable an overall mining cost reduction. The initial trial blast results were less than satisfactory with both environmental issues occurring and the desired shovel productivity not being achieved. An audit of the blasts indicated that wet ground and the presence of soft clay inter-bedded with harder rock caused the poor blast results. Also, water-affected explosive product combined with explosive energy loss into soft ground led to flat spots and tight digging in the hard band areas, resulting in the lower dig rates. Lemington Mine and Orica Explosives developed a plan to match the rock with the appropriate explosive type and energy. This resulted in a number of blasts over a six-month period using a new non fuming explosive product, æNovaliteÆ. The results have been excellent with the environmental issues being totally resolved and dig rates improved, enabling reductions in mining costs. This has allowed the mine to continue with their exemplary record of environmental management whilst achieving operational efficiencies.

Jan 1, 2001

By J A. Brown

Osborne Mine commenced hydraulic filling of three stopes in April 1999. Two of these stopes experienced barricade failures in July 1999 and January 2000. As a result, a review of hydraulic filling was commissioned in April 2000. The design of a trial of revised specifications and practices is in the final stages, prior to the trial commencing in mid-2002.

Jan 1, 2002

Stability on surface mining projects is primarily controlled by five factors. These include structural geology, the most important of the factors, the existence of weak layers, primarily clayey gouge or clay infill, groundwater, blasting and weathering. Case examples of stability on many surface mines including some coal mines are presented. The experience and lessons learned are applicable in some way to stability of surface coal Mines.

Jan 1, 1986

By Sobek S, Lotzien RM

Although the conventional procedures for designing agitator flotation plants are well-known and reliable, little experience for designing modem pneumatic flotation plants has been gained up to now. A reliable procedure originating from graphic methods for the design of distillation columns is presented. Examples demonstrate on laboratory and semi-technical scale the application of this extremely practical method for designing a fly ash and a magnesite flotation plant.

Jan 1, 1993

By P Benjamin, H Bohannan, C Farr

Geoffrey Blainey's historical account of the mining activity on the west coast of Tasmania, æThe Peaks of LyellÆ documents the changes over 130 years of activity in the region. Commissioned by the Mount Lyell Mining and Railway Company, emphasis is placed upon the development of the Mount Lyell Mine in Queenstown. Chapter 19 æWidening HorizonsÆ details the review the Mount Lyell Company undertook in 1904/05 to ensure the future of the operation, following the pessimistic outlook regarding diminishing reserves and poor grade ore. The analogies documented between the Mount Lyell Company at that time, and Gold Mines of Australia 90 years on are remarkable, with both companies demonstrating a commitment to the Mount Lyell area through active exploration, the proactive search for alternative technology and the recognition of the valuable human resource. As Blainey writes (Blainey, 1993), æwith its expanding chemical works, its huge Tasmanian mines, its railways and smelter, its coke works and its mine crusade, Mount Lyell was probably one of the nation's five great industrial companies in 1906 or 1907. This brief phase of industrial and mining expansion had its seed in the threat of extinction . . .Æ After a number of reprieves, the Mount Lyell mine did stop production in 1994, but that only provided an impetus for a review and rebirth.

Jan 1, 1998

The title of my address today is "Oil and Gas Valuations - A Simplistic View of Some Critical Issues". Alternatively I could have called this address "Pitfalls for investors' and corporates in accessing Independent Experts Reports" 'as in this brief 12 minute talk I will briefly comment on some common misconceptions with regard to the valuation of exploration areas and production interests, and comment on how the draft release guidelines address these issues.

Jan 1, 1989

Selective leach analytical techniques applied to surface geochemical samples in the search for deeply buried mineral resources gained popularity in the late 1990s. Several commercial assay laboratories introduced their own selective leach methods, adding to the few established commercial methods at that time. Many of these laboratories promoted their methods with orientation data showing favorable responses to both precious and base metal mineralisation, concealed beneath extensive thicknesses of overburden. However, many explorationists remain confused about the utility of these geochemical methods. This confusion is due primarily to the lack of objective orientation surveys over significant mineralisation, comparing all commercially available selective leach methods and to the lack of a creditable theory explaining the formation of these selective leach anomalies. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. An orientation survey was designed to fill the first void û an objective survey over significant mineralisation. With the help of 17 mining companies and assay laboratories, an orientation survey was conducted over five significant covered gold deposits in Nevada, USA , representing over ten million ounces of gold. Hopefully the results of this survey will help provide fuel for those working on the second void û a theory to adequately explain the formation of these selective leach anomalies.

Jan 1, 2008

By Qixiang Y

The strength of coal mass saturated with gas is an essential parameter in studying the mechanism of gas and coal outburst,and its prediction method. Up to now, there has not been a method for determining the strength of coal mass saturated with gas.This paper describes a new method whereby the strength of in-situ coal mass can be determined and stored continuously and automatically. The simulation results obtained in the laboratory indicate that the new method allows a fast, reliable, inexpensive and convenient determination of the strength of coal mass.

Jan 1, 1992

By Susanto A

As part of the current NERDDC funded project studying Dragline/Hopper/ Crusher/Conveyor systems for overburden removal, an investigation was carried out to assess the feasibility of automating the swing-to-dump phase of the dragline digging cycle in order to main- tain consistent performance of spotting the bucket above the hopper prior to dumping. The study involved design of automatic position controls for the hoist, drag and swing drives and simulation of detailed mathe- matical models of the three electromechanical systems and their associated electrical control schemes. The design of the hoist and drag systems to position the bucket in the boom plane is relatively straightforward. Simulation results show fast and accurate performance, with no evidence of interaction between the two drive systems through the ropes. The design of the swing position control system involves special strate- gies to cater for variable inertia and to damp the pendulum oscillations of the bucket. The use of a bucket pendulum model and variable dynamic compensation embedded within the feedback control loop, along with optimal speed/angle slowdown trajectories, has yielded fast and damped positioning responses under simulation.

Jan 1, 1989

By Henley R, Harris L

High resolution airborne magnetic and radiometric data have been shown to optimize exploration for epithermal gold deposits in the vicinity of Charters Towers, northeastern Queensland. The radiometric data allow extrapolation of poorly outcropping geology to provide a cost-effective mapping technique, even at exploration scales (eg. 1:25,000). At a regional scale (eg. 1:100,000) the magnetic data reflect the regional tectonics and divide the area into domains for the application of different genetic models. For example: 1. the Ravenswood Batholith is characterized by multiple intrusions dating from Ordovician to Permian age. The polarity of the magnetic anomalies implies an age for the intrusions and indicates a deposit style for exploration. 2. extensional and wrench tectonics along the northern margin of the Drummond Basin are interpreted from the magnetic data and indicate favourable blocks for detailed exploration. Genetic exploration models may be tested in favourable environments by the recognition of geophysical signatures. These signatures reflect structural, lithological and alteration patterns arising from controls on ore deposits and can be applied at regional or detailed scales.

Jan 1, 1989

Thiess Dampier Mitsui's Moura-Mine is located in the south-eastern corner of Queensland's Bowen Basin, some 180 kms west of Gladstone. Current requirements of the open cut operation are to drill and blast 25 million cubic metres of overburden per year, consuming some 12,000 tonnes of explosive in order to meet the requirements of the mine's four operating draglines and one overburden shovel. By early 1985 it had become obvious that the existing drill and blast equipment and technology could not cope with the long-term needs of the open cut mining operation. Three 61R drills were in need of rebuilding or replacement. Bulk ANFO trucks working two shifts per day were unable to match the requirements of the four draglines dne to long travel distances, slow discharge rates and their inability to load water-resistant products into the increasing number of wet holes. This paper outlines the significant steps taken to introduce new equipment and technology and the resulting improvements in the mine's productivity and economics.

Jan 1, 1986

By Biswas AK

The solubility of nickel in matte smelt- ing slags, both as oxide and in the metallic form, is predicted using the results of a recent experimental work carried out with lime- free iron silicate slags as well as slags containing lime. Predicted solubilities are much lower than the nickel content of smelting slags, indicating that entrapped and possibly dissolved matte could be the major cause of nickel losses in such slags.

Jan 1, 1975

By Lynch P

Oaky Creek Coal Pty Ltd. currently mines high quality coking coal from both underground and open cut operations at its Oaky Creek Mine. Coal is transported by rail to the Dalrymple Bay Coal Terminal south of Mackay and to the Gladstone Coal Terminal. Oaky No.1 Underground Mine, Open Cut and Highwall Mine have concentrated on seams from the German Creek Formation, one of the major productive coal measure formations in the Bowen Basin Coalfields. (Fig. 1) location map.

Jan 1, 1998

Broken Hill has a long history of mining and it is without doubt a world-class deposit. It has seen production since 1885, notwithstanding the strikes that made the city infamous in days gone by and has given rise to three of the nation's leading mining companies; BHP, North and CRA. Prior to the formation of Pasminco in 1988, the mining and exploration activities were undertaken by separate companies who were business competitors and tended to operate in relative isolation. There were a few notable exceptions such as the Central Geological Survey of 1936 - 38 (Gustafson, 1939; Gustafson et al, 1950) and the Mine Managers' Association. The latter sponsored many university based research projects. At a local level there was good communication and cross fertilisation within this remote outback centre through personal contacts and professional bodies such as The AusIMM. Pasminco was formed by the merging of the lead-zinc interests of CRA Ltd and North Broken Hill Ltd. In Broken Hill this meant the joining together of North Mine and ZC Mines, the two largest mines then operating on the Line of Lode, to form Pasminco Mining Broken Hill Operations. The exception was the central part of the orebody, the original BHP, South Mine and

Jan 1, 1997

By Thatcher R

In areas where land suitable for development is a scarce resource, an upgraded post-mining land use can result in economic benefits to both the mining company and to the community.A study undertaken at Aberdare Colliery near Ipswich during 198611987 assessed the costs and benefits of developing the site following mining for grazing, forestry and residential uses. The proposed fmal land use plan comprised a combination of these uses that can be upgraded to higher valued uses once subsidence monitoring of backfilled open-cut areas and dumps indicates that total settlement has reached acceptable levels for development to proceed.The study involved the documentation of existing site environmental parameters and the delineation of site opportunities and constraints. The unpredictable nature of settlement over backfilled open-cuts and overburden dumps represents the major constraint to urban development on mined areas.

Jan 1, 1990

It is important to prevent the overload ing of mills being operated near maximum tonnage. Changes occurring during overload differ in their usefulness as guides to control action. The Primary Ball Mills of Bougainville Copper Ltd. provide an example of some of the problems and progess in avoiding overload.

Jan 1, 1978

Some of the major factors affecting ore reserve estimation in gold mines are discussed together with their impact on computational methods.The major priority in ore reserve estimation is to get sampling and geological problems resolved. Poor basic information cannot be remedied by mathematical methods.Generally the more complex a deposit becomes the greater the need for subjective assessment and the less applicable are more complex ore reserve methodologies.

Jan 1, 1984

This paper investigates dry drilling as a feasible alternative to meet current requirements for improvements in mining productivity in an increasingly competitive world.A field test program was conducted in the surface facilities of a hard rock mine in Sudbury, Canada, to investigate the potential use of dry drilling in underground bulk mining as a conceivably faster and more economical method than wet drilling. The test work consisted of the monitoring of advance rates and bit life while a series of 165 mm diameter holes, wet and dry, were drilled with compressed air at both mine (0.69 MPa) and high (1.72 MPa) pressure levels. The results indicate that penetration rates can be increased by approximately 24 per cent by drilling dry with high air pressure and by approximately 27 per cent by drilling dry with mine air as compared with wet drilling under the same conditions. Dry drilling also has the effect of increasing bit life by up to 69 per cent. An economic analysis for typical hard rock mines indicated that drilling productivity and cost savings can be increased by approximately 23 per cent when dry drilling is utilised.The testing program indicates that dry drilling has the potential to become a feasible technique with regard to performance, productivity and costs.

Jan 1, 1991

The introduction of large diameter drill holes and mass firings in underground metalliferous mines has led to an increase in the number of reported sulfide dust explosions in Australia and overseas. Adaptation of the coal mining technique of using limestone to inhibit or prevent dust explosions has not been entirely successful as the development and inhibition of a sulfide dust explosion is somewhat different from that of a coal dust explosion. Tests were carried out on two pyritic ore samples, sulfur contents of 41 and 36 per cent, in 8 and 20 litre explosion chambers to evaluate the effect of the addition of limestone on the maximum explosive pressures developed and rates of pressure rise. Significant values were obtained in both chambers with dusts containing 60 per cent ore and 40 per cent limestone. The percentages of limestone required to inhibit the pyritic dusts were considerably higher than those values generally accepted by the mining industry and the current methods used to inhibit sulfide dust explosions should be re-evaluated.

Jan 1, 1986