Rational development of noble metal placer mining waste in the east of Russia

Abstract

The discussion involves the issues relating rational development of natural noble metal placers and the placer mining waste, their resource potential and basic trends in mining, processing and beneficiation. It is found that the determinants of profitable development of a technogenic object (mine waste) is its pre-restructuring aimed at generation of a new structure and at increase in value of reserves adapted to the chosen mining and processing technologies. The author substantiates the necessity and advisability of innovative technologies for placer mining waste development based on formation of concentration zones of commercial value components in dumps. The developed ways of technology modernization for gold washing machines enable increase in recovery of gold and other valuable associate components within a single work cycle.Russia's Far East is rich in a variety of natural resources and boasts mature mining industry. In some areas of the Far East Federal District (FEFD), natural economy is solely represented by mineral mining. The prime minerals are gold, platinum, silver, diamonds, tin, lead and zinc, wolfram, coal, boron, fluorite, oil, gas and others. The District holds 3770 booked gold deposits, out of which 129 are primary deposits (including 14 complex deposits) and 3641 are placers. Percentagewise, Magadan Region takes 31% of all gold deposits, Republic of Sakha-21%, Amur Region-16%, Chukot Autonomous Area-14% and the Khabarovsk Territory-10%. Considerable deep-seated gold placers in FEFD take 60% of all known reserves and offer good prospects for more discoveries.Gold placer mining share in the overall gold mining in Russia was 70-75% in the late 1990s and faced a decline later on both due to availability of readily accessible and rich placers and, as a result, cut down content of geological exploration. Up to date, placer gold mining in many areas in FEFD remains at a level of 25-35% of the overall gold mining, except for the Republic of Sakha (Yakutia) where placer gold mining share is over 50%. As a consequence of the decreased placer mining, some areas in the Far East face a social and economic stress.Russia produced 130.8 tons of gold in 2000, raised the production to 199.5 t (by 52%) in 2012 and produced nearly 214 t in 2014. Gold production in FEFD within the same period of time varied from 76.9 to 109.6 t, i.e. gold production grew by 42.5% in 2012. Within the indicated period, placer gold mining in RF reduced by 21.6% (from 80.4 to 63 t) while it increased in FEFD by 24% (from 28 to 34.6 t) [1,2].FEFD needs feasibility study of gold placer mining, which is both the scientific mission and the way of bringing authorities and subsoil users to solving of economical, social and ecological problems in the region. In this context, a most rational decision is to turn to technogenic deposits-placer mining waste.

Studies of enrichment of sulfide and oxidized ores of gold deposits of the Aldan shield

“…Результаты выщелачивания хвостов флотации, а также концентратов флотации и гравитации, полученных из шихты исходных руд, приведены в табл. 6 Извлечение золота из хвостов флотации составило 25-60 %, прямое цианидное выщелачивание концентратов обогащения шихты исходных руд в режиме агитационного перемешивания пульп (Т:Ж = 1:2, C NaCN = 1г/л, рН = 10,5-11,0, время -24 ч) обеспечило извлечение золота 86,4 % для гравитационного концентрата и 75,0 % для флотационного концентрата. Извлечение серебра при этом составило соответственно 36,5 и 32,5 %.…”

“…По данным В.А.Чантурия за последние 20 лет содержание золота в рудах снизилось в 1,2-1,5 раза, доля труднообогатимых руд в общей массе сырья, поступающего на обогащение, возросла с 15 до 40 %. Исчерпание запасов приводит к необходимости промышленного использования труднодоступных месторождений руд с потенциальными запасами, что повышает логистические затраты и определяет рентабельность отработки [3,5,6], таковыми являются месторождения Республики Саха (Якутия). На основании данных из открытых источников в 2017 г. на территории Якутии добычей золота занимались 58 предприятий, в том числе 11 -на рудных месторождениях и 47 -на россыпных.…”

Estimation of operating costs and energy consumption in beneficiation of alluvial gold deposits

“…The share of alluvial deposits containing fine and plate-like gold is constantly increasing, and deposits with a high content of clay particles, heavy minerals, as well as technogenic deposits are also involved in mining. As a result, there is an increase in metal losses and, in general, a decrease in the efficiency of the development of such deposits [1][2][3][4][5][6].…”