Dependence of Unit Cost of Gold-bearing Gravel Processing on Energy Consumption
This paper is a continuation and extention of the previous paper on energy-efficient placer mining methods which was presented in 2007 at the World Gold Conference in Cairns,Australia (Neretin,2007a).The paper reports the results only on gravel processing as they were not fully discussed in the previous paper.It is common knowledge that placer gold mining requires processing of large tonnages of gold-bearing gravels by wash plants of different types.In Russia,gold-bearing gravels are mostly disintegrated and screened by the following types of wash plants: a water canon,a derocker or a scrubber trommel.Gold-bearing gravel processing is regarded as highly energy-intensive due to high energy consumption for transportation of large tonnage of material and high pressure water flow rate.The industries requiring a significant expenditure of energy normally estimate the process efficiency by energy consumption per product unit.In order to obtain quantitative data on energy consumption for gravel processing and to estimate placer mining costs,in 2003～2006 four placer gold mines located in the Irkutsk Region were thoroughly investigated through time and motion studies.At all these placer mines gravels were processed by a water canon,a derocker or a scrubber trommel.The objective of the study was to investigate the following parameters: · wash plant throughput rate per hour; · hourly diesel fuel and power consumption per cubic meter of gravel processed; · volume per cent and shape of oversize material; · different combinations of gravel processing methods.The results from this study were as follows: · specific energy consumption per cubic metre of gravel processed for different combinations of gravel processing methods was estimated; · a correlation between energy consumption and unit cost of gravel processing was determined; · effect of yield and shape of oversize material on wash plant throughput rate per hour was de fined; · energy-efficient gravel processing methods were developed.Based on these results,an improved method of gold-bearing gravel processing was proposed.Implementation of this method at a placer mine saved US$ 123 000 in operating expenses only during a short-time Siberian placer mining season.At the same time,this method improved gravel disintegration,screening and processing operations used at the mine.Another advantage of the proposed method was higher gold recovery due to reduced yield of undersize material.In order to improve efficiency of gravel processing,a wash system including a derocker for primary gravel processing and a lightweight scrubber trommel was developed.There are two economic benefits of replacing water cannons with the proposed wash system.The first benefit includes lower operating costs for gravel processing due to lower specific energy consumption,while the second benefit is lower gold losses during slurrifying (disintegration and screening) and sluicing of the undersize material.
Placer gold mine Water cannon Scrubber trommel Derocker Gravel processing Energy consumption Shape of oversize material Correlation
A.V.Neretin
Irkutsk Research Institute of Precious and Rare Metals and Diamonds (IRGIREDMET JSC),Russia
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
4374-4385
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）