نتایج جستجو برای: metal ore

تعداد نتایج: 206834  

2013
Dónal O’Sullivan Alexandra M. Newman Roderick G. Eggert

Underground mine production scheduling possesses mathematical structure similar to and yields many of the same challenges as general scheduling problems. That is, binary variables represent the time at which various activities are scheduled. Typical objectives seek to minimize costs or some measure of production time, or to maximize net present value; two principal types of constraints exist: (...

Journal: :Environmental Health Perspectives 1999
A L Benin J D Sargent M Dalton S Roda

In developing countries, rapid industrialization without environmental controls has resulted in heavy metal contamination of communities. We hypothesized that residential neighborhoods located near ore industries in three northern Mexican cities would be heavily polluted with multiple contaminants (arsenic, cadmium, and lead) and that these sites would be point sources for the heavy metals. To ...

Journal: :Minerals 2021

The Igoudrane mine with a total production of 700,000 t ore grading 485 g/t Ag is currently one the most productive mines in Imiter district eastern Anti-Atlas Morocco. silver-rich ± base metal deposit occurs dominantly as vein- and hydrothermal breccia-hosted orebodies at interface between lower Ediacaran turbidites Saghro Group unconformably overlying, felsic volcanic, volcaniclastic rocks la...

Journal: :Geomechanics and geophysics for geo-energy and geo-resources 2023

Abstract Microwave irradiation is a potential technology for use in rock fracturing. It of great significance the application microwave metal mines to understand cracking characteristics ores and mechanism action ores. Taking Hongtoushan copper ore, Sishanling iron Dandong gold ore as research objects, with different morphologies (bulk/particle samples) particle sizes were investigated. The was...

2012
R. Dimitrakopoulos

An orebody model constitutes a threedimensional accumulation of mining units (blocks). The available metal content in a mining unit and the economic parameters, such as metal price, mining cost, processing cost, marketing or selling cost, as well as the metallurgical recovery, are used to calculate the economic value of a particular mining block. A mining block with a positive value is classifi...

2014
Likun Qiu Yue Zhang

Open Relation Extraction (ORE) overcomes the limitations of traditional IE techniques, which train individual extractors for every single relation type. Systems such as ReVerb, PATTY, OLLIE, and Exemplar have attracted much attention on English ORE. However, few studies have been reported on ORE for languages beyond English. This paper presents a syntax-based Chinese (Zh) ORE system, ZORE, for ...

2011
E. Bakhtavar

In this paper, problem of short-term production planning for dimension stone quarries was mathematically modeled using a binary integer programming. The model includes an objective function, which was founded as the minimization of the costs due to the total cutting planes of the blocks. This objective may cause to maximization of the net present value (NPV) in dimension stone quarries. During ...

2015
Martin Simonsson

Iron ore pellets are made from refined and ground ore that is balled into spheroids and then heat treated. Pellet properties are measured through standardized physical, chemical and metallurgical tests to guarantee a high quality end product. However to better understand the oxidation and sintering of iron ore pellets one has to study the microstructures. This paper provides a proof of concept ...

2016
Jessica Egan Claude Bazin Daniel Hodouin William Skinner

The recovery of gold by ore leaching is influenced by the size of the particles and the chemical environment. The effect of particle size on the dissolution of gold is usually studied using mono-size particles as the gold in solution comes from the ore of a unique leached particle size. This paper proposes a method to estimate the gold dissolution as a function of particle size using a bulk ore...

2002
M. A. GIAVENO T. L. LAVALLE E. DONATI

−− Copper recoveries using two methodologies of acid leaching of a low-grade ore are reported in this work. The ore, abounding in oxidized species, was from Barda González reservoir in Neuquén province, Argentina. In the first methodology, cells of Acidithiobacillus thiooxidans were inoculated into a column containing the ore and sulfur as energy source. In the second one, a bioreactor with imm...

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