- •Gold mining
- •Text 1. Some facts from the history of gold mining
- •Diamond Placer
- •Text 3. La paz placers
- •Text 2. Placer mining вy excavating machinery
- •Fig.1. Ruston-Bycyrus dragline excavator
- •Fig. 2. Dragline making first cut
- •Fig.5. General arrangement of property for dragline mining
- •Text 3. Power shovels
- •Cableways
- •Text 4. Excavating equipment in тнe mid 80s
- •Electric mining shovels
- •Hydraulic excavators
- •Fig. 13. Ransomes and Rapier w2000 walking dragline stripping overburden at phosphate mine in Jordan
- •Fig. 14. Shows the rh120c introduced in 1933 as an intermediate size between the rh75 and rh300, incorporating “Tripower" geometry
- •Text 2. Dredging in the north
- •Stripping
- •Dredging
- •Vocabulary
- •Text 3. Thawing
- •Other operating problems
- •Nodules
- •20° Angle Gave Best Results
- •Fig. 17. Nodule dredge configuration shown was chosen after a series of increasingly complex dredge designs
- •Larger Dredge Lines Cause Problems
- •Dredge Vessel Specifications
- •Ship Positioning By Dead Reckoning
- •10 Tpd Average
- •Fig. 18. Stages in mining diamondiferous gravel
- •Transport
- •Milling
- •Effects
- •What is Cyanide?
- •Prevention/Solution
- •Text 2. Sluicing
- •Sluice Boxes
- •Water Required
- •Tailings
- •Text 3. Excavation and treatment of gravel
- •Fig. 29. Sluicing by direct loading method
- •Fig. 30. Method of working with ample water supply and steep valley
- •Text.2 working of terrace and alluvial deposits
- •Fig. 33. Method of working river terrace and eluvial deposits
- •Fig. 34. Example of exploitation plan
- •Text 2. Hydraulic mining
- •Fig. 35. Sketch of giant or monitor
- •Text 3. Hydraulic elevators
- •Fig. 41. Hendy hydraulic gravel elevator
- •Fig. 42. Section of elevator pit (Joshua Hendy Iron Works)
- •Text 4. Sluice boxes for hydraulicking
- •Text 2. Miscellaneous methods of mining
- •Text 3. Khetri copper complex
- •Text 4. Kherti and kolihan mines
- •Fig. 46. Longituainal section of Kherti mine, showing principal shafts, main levels and stoping areas
- •In Kolihan mine, small footwall ore-shoots are worked by a sub-level top-slicing method using jackhammers and remote controlled Cavo loaders.
- •Shafts at the Kherti and Kolihan mines
- •Fig. 48. The service shaft, Khetri mine
- •Central services
- •Personnel and housing
Fig. 48. The service shaft, Khetri mine
Both mines have a central ore pass system (fig. 48). In the mine this extends from the 350 m level to the 0 m level. A primary jaw crusher at 18 m reduces the ore to 150 mm size before it passes, via a bunker and measuring pockets, to the 14t skips, for hoisting. In Kolihan mine the main ore pass is from 364 m to 246 m, at which level there is a rim- of- mine bin feeding to a 42 in x 48 in jaw crusher at 229 m. This reduces the ore to 150 mm, after which it is hoisted in 6t skips from the loading pocket at 200 m.
Some 40 to 50% of development is in waste, and this is generally hoisted out of the mine in Granby cars in the service shaft cages. At Khetri this is done from the 180m and 0 landings, the waste being delivered to these levels through waste passes. Waste from the upper (364 m and 306 m) levels of Kolihan mine is hauled to surface up the decline by low-profile trucks. The waste muck generated below the 306 m level is dropped through waste passes to the 184 m level, from which it is hoisted in the vertical shaft.
The water inflow to Khetri mine amounts to some 150000 m3/mouth. Sumps are provided at the 0 m, 180 m and 300 m levels. Two 135 kW pumps at the 0 m sump deliver to the 180 m sump, where there are six 135 kW pumps installed. The sump at 300 m, which handles all water from the upper levels, has two 130 kW pumps. A total of nine pumps, ranging from 22 kW to 187 kW, handle an average flow of 158,400 m3/mouth at the Kolihan mine.
Main ventilation is provided at Khetri mine by a 175 kW Sirrocco axial flow fan at the production shaft, which gives an air flow of 7800 m3/min at 25 mm water gauge. Booster fans are used in development headings in conjunction with 600 mm rigid ducting. At Kolihan there is a 175 kW axial-flow fan serving the decline section of the mine, which provides a flow of 4250 m3/min, and two smalter fans serving the shaft section, giving a further 2250m3/min.
The personnel employed at the two mines are as follows:
Mine |
Kherti |
Kolihan |
Staff Workers: Doy-shift Shift-work |
125
621 417 |
123
286 748 |
The current levels of production are 2500 t/d of ore and 500t/d waste at Khetri, 2500 t/d ore and 200 t/d waste at Kolihan, From 1987/88 it is planned to raise these figures to 5000 t/d ore. 600 t/d waste at Khetri and 3000 t/d ore, 200t/d waste at Kolihan. Cut-off grade at both mines is 0,5% Cu, the mill head grades being 0,8% Cu from Khetri and 1,97% Cu from Kolihan.
Central services
Electrical power is supplied by the Rajasthan State supply authority, the maximum demand on this utility being 32 MVA. However, there are many problems with this source of supply, and HCL has installed diesel generator sets with a total capacity of 26 MW.
Tbe daily consumption of industrial water is 31000 m3. This is obtained from 18 tube wells sunk into aquifers at two sites, some 25 km and 42 km away respectively.
Potable water is obtained from 14 tube wells sunk into the bed of the Kharkhara River, the daily consumption being 9000 m3.
Compressed air for the Khetri mine is supplied from a compressor- house in which there are 17 compressors, ranging in size from 30 to 130 m3/min (1,070 to 4500 m3/min), the total consumption being around 650 m3/min at 690 kPa (100 lb/in2). The Kolihan compressor house has seven machines ranging from 21 to 226 m3/min, the latter being an Atlas Copco machine driven by a 1200 kW motor. Total usage of compressed air at Kolihan is around 400 m3/min at 690 kPa.
There are a number of workshops undertaking maintenance and repair work; a fabrication shop, with 28 various machine tools; a carpentry shop; a mechanical engineering shop, with a 500 t press; a foundry, with a 1.5 cupola and three smaller furnaces; an air conditioning department, responsible for maintaining 250 air conditioners and 100 water coolers; and a garage.
The central store holds about 50000 items, the annual turnover being about 13000 items. The inventory holding is valued at about Rs 140 million, while annual consumption is worth around Rs 190 million.