The New Burgin project is located in the East Tintic mining district, Utah, approximately 60 miles southwest of Salt Lake City. Historically mining has been difficult, in part resulting from the lack of ability of previous operators to sufficiently de-water the mine. Rock conditions are said to be fairly poor and thus underhand cut and fill mining has been proposed. The New Burgin Project was a JV between Chief Consolidated Mining Company (75%) and Korea Zinc (25%). Chief Consolidated Mining Company was 83.5% owned by Andover Mining Corporation. Mineral extraction was carried out in the 1960s by Kennecott, but closed down in the 1970s due to high operating costs.
Mining of New Burgin will be by underground methods, with stopes mined using underhand drift and fill methods. The stopes will be by completing 10ft by 10ft panels in the ore, each of which will be backfilled with cemented filtered tailings.
It is intended that two levels will be developed once mining proceeds at new Burgin. Mining will be based on a 6-day per week production schedule followed by a maintenance day. A total of 846t/d of ore will be mined over the 6-day period.
Previously mining was complicated by excessive water inflows of warm corrosive saline water with elevated levels of arsenic, lead and total dissolved solids, with the cavernous nature of the dolomitised limestones leading to poor ground conditions. A provision to treat this water at an estimated flow of around 5m3/hr is a priority. The required pumping of a large volume of water from the mine is a significant operating cost component due to the large amount of power that will be consumed.
As a consequence a three year pre-production period is required to de-water the mine as well as install a new shaft. The first year of pre-production will involve the completion of five dewatering wells, with four additional wells to be installed in the following year and one the year after. Pumping will commence at a rate of 5000g/m in the second year and increase to 9000g/m in the third. Once operating, the number of wells and pumping rate is expected to increase.
Conventional processing at 0.8kt/d. The Burgin mill was operational between 1968 and 1978; mill recoveries ranged between 86% and 90% on clean sulphide ore and down to 50% when mineralisation was interlocked with gangue or on oxide ore. A study in 2001 estimated metal recoveries were around 92% Pb and 84% Ag in the lead concentrate and 60% zinc in the zinc concentrate.
Tables and charts
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