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By H Arvidson, Rondinelli Sousa, Nic Pollock, Cesar Carrasco, Boz Elloy

Global public mineral reporting codes have driven strong governance of public disclosures of minerals information. Recently, we have seen an increase in disclosure of information related to Environmental, Social and Governance (ESG) issues, and governance of ESG information in mining companies has arguably reached a similar level of governance and diligence afforded mineral reporting. We define Resource Governance as the conjunction of environmental, social and minerals governance. A modern systems approach to Resource Governance, which combines mineral and ESG information, would provide not only reporting and governance capability, but also has the potential to sense/respond, predict, and manage ESG risks.

Feb 1, 2024

By R. Klimpel

Recent work has shown that the measurement of flotation kinetics in the laboratory is useful in providing guidelines on how operating sulfide flotation plant performance can be improved. This work outlines the influence of various factors on flotation kinetics such as collector/frother type and concentration, particle size, and frother blending.

Jan 1, 1981

By A. P. Gentsch

Commercially mined calcium carbonate is normally found near the surface in the United States. It is nun& either by open pit or underground methods, depending upon its geologic setting. Processing ranges from simple crushing to the more sophisticated ultrafine processes. Intermediate steps are pulverizing, screening, beneficiation, classification, fine and ultrafine grinding, and surface treating. These processes are performed both dry and/or wet resulting in powdered or slurry end products.

Jan 1, 1986

By C. E. Jordan

Direct digestion of phosphate ores by the acid-alcohol method offers improved leaching selectivity for the exclusion of iron and aluminum in the product acid. The leaching kinetics of this process will have a major role in the eventual application of this technology. The Bureau of Mines investigated apatite dissolution to determine the reaction rate and mechanisms of the leaching kinetics. The dissolution kinetics were monitored on various sized fractions of pure apatite. The "shrinking-core" kinetics model was applied to the data to determine the rate controlling mechanisms. For each size fraction, the initial reaction rate was controlled by the dissolution reaction. After an hour the dissolution rate slowed indicating a diffusion controlled reaction caused by the formation of calcium sulfate hemi-hydrate coating on each particle. For complete dissolution of the apatite, the phosphate rock should be ground to near 10 µ m size.

Jan 1, 1993

By S. G. Ozkan

Boron minerals of economic importance are primarily colemanite, tincal, and ulexite. Turkey and the United States are the leading producers of boron minerals and compounds. Other production includes datolite in Russia and synthetic colemanite in Chile. This paper will discuss various types of chemical and physical treatments of boron ores to produce the marketable minerals and compounds that are consumed in commercial products.

Jan 1, 1995

By Harry E. LeGrand

The purpose of this paper is to outline briefly some basic principles of ground-water hydrology that have application in mine hydrology and to suggest that an understanding of these principles can help to forestall problems that are internal as regards mining operations and external as regards damage or harm to surrounding areas. The development of a mine below the water table pleads for accurate values to answers of hydrologic problems. Such internal problems involve both an inflow of water without adequate drainage facilities and a deficiency of water for the required mining or milling use. Methods which give acceptable quantitative values for the solution of many ground-water problems depend on rather simple geologic structures, characterized chiefly by homogeneous rocks of considerable areal extent. Unfortunately, mining operations are likely to be centered where rocks are not homogeneous. Consequently, methods that attempt to show values of the storage and transmitting capacity of rocks in mining areas must be applied with caution. In spite of complex geology and apparent uniqueness of individual mines and quarries, adherence to some concepts of ground-water occurrence and movement should be helpful to mine operators. Mining operations that extend below the water table disturb the natural hydrologic regimen. Prior to development, the water table slopes away from the site of a mine in at least one direction, but as soon as development begins and water is removed from the mine, the mine becomes the apex of a depressed cone in the water table, causing a convergence in the flow of water toward the mine, The behavior of the cone of depression, as it tends to deepen and to increase in areal extent when the mine is deepened, is related to the rate of withdrawal of water necessary to keep the mine dry. The significance and nature of the cone of depression in the vicinity of pumped wells has been studied by ground-water hydrologists for years, but the cone caused by pumping water from mines has generally been less systematically appraised. The geologic and hydrologic settings of mines range greatly so that a simple standard procedure for dealing with problems

Jan 1, 1972

By Martin B. Zimmerman

It is becoming evident that traditional methods of econometric analysis are inadequate in estimating-the long-run supply of minerals. Econometrics is limited to extracting estimates from observations of the theory predicts that the least cost deposits will be exploited first.1 The estimation of parameters from past data then must lead to biased projections of the future. Mining conditions in the future will be worse than in the past and it is the impact of the future conditions on cost that we need to know. In this paper we present a methodology for dealing with this problem. We estimate a "cumulative cost" function that yields the long-run marginal cost of mining as a function of cumulative output produced over time.2 This is relatively easy to do for coal mining in the United States where exploration for new deposits is not a major factor in supply. The first step of the procedure relates cost to the rate of output and to the geological conditions of the mine. The second step combines geological information on remaining deposits with the cost function to yield the cumulative cost function. A central theme of both these steps is the interaction of economics with geology. The best deposits are selected first and in each step of the estimation allowance must be made for this fact. The problem of depletion is part of the general problem of structural change. The change through depletion in the nature of the exploitable mineral stock is only one factor that calls for an analysis sensitive to the changing circumstances of the industry. The factors impinging most heavily on the coal industry today are the strict environmental regulations legislated

Jan 1, 1977

By E. H. Smith

St. Joe Minerals Corp., a subsidiary of Fluor Corp., treats high-grade gold, silver, and copper ore at its El Indio plant at an altitude of 4 km in the Chilean Andes. The ore is complex, being a mixture of massive pyrite-enargite and quartz, both containing very fine gold and silver. Treatment produces a copper flotation concentrate containing high levels of gold, silver, and arsenic, and also dore bullion. Part of the flotation concentrate is roasted to remove the arsenic content, and arsenic trioxide is collected as a by-product.

Jan 1, 1987

By T. C. Vogt

Earlier we described the uranium mineralogy of an areally broad sampling of Crownpoint ore, including the characterization of organic carbonaceous material associated with the uranium mineral. (1) We also reported on the leaching behavior of Crownpoint ores with a mild alkaline leaching system, oxygen (02)-sodium bicarbonate (NaHC03). (2) There was a wide range of leaching responses, with samples from some areas leaching at a slow rate with low uranium recovery. Evidence indicates that in these samples the organic material is intimately associated with the uranium mineral and shields it to some extent from contact by the leachate. (1,2) One method to obtain faster leach rates and higher recoveries is to use a chemically severe leaching system such as sodium hypochlorite (NaOCI) as an oxidant. (3) The use of sulfuric acid (H2SO4) and an oxidant for leaching ore in surface milling operations is widely practiced to effect high recovery of uranium (U308) from the ore. (4,5,6) The U308 is mobilized as the disulfate complex, U02(S04)224-, or possibly, the trisulfate complex, U02(S04)34-, is the soluble species. (7) Sulfuric acid leachate formulations were used in the first in-situ leaching operation in the Shirley Basin in Wyoming. (8) More recently H2S04 formulations have been used in the Rocky Mountain Energy field tests in the Powder River Basin (Bear Creek) and in the Teapot forma¬tion at Nine Mile Lake site near Casper. (9,10) Laboratory studies related to the use of H2SO4 for in-situ leaching have been reported (11-17) and Yan has .reported packed column leach studies on Crownpoint ore using H2504 and oxidant. (18)

Jan 1, 1981

By A. Almeida, D. Castro, K. Ingmarsson, D. Ferreira, R. Tamir

Mine-to-mill improvements can be initiated at any stage, but it is our assertion that drilling accuracy is a practical anchor in any operating mine or quarry for a structured continuous improvement process. This paper will: 1. Define deviations from plan and provide some best practices for maintaining drilling accuracy. 2. Introduce tools and methods to monitor and calculate consequences of accurate versus inaccurate drilling. 3. Demonstrate the use of these tools and methods and their impact on one cost item, the mitigation of oversized material by a hydraulic hammer. 4. Provide recommendations for implementing improvements.

Feb 1, 2023

By Sunfangze Liu, Xumeng Chen, Yongjun Peng

Efficient separation of naturally hydrophobic gangue, such as talc and carbonaceous materials, from sulphide minerals in flotation is becoming a significant challenge in many processing plants due to the need to process lower grade and more complex ores. Considering the hydrophobic nature of these gangue minerals, prefloating them at the beginning of the flotation circuit in the absence of collectors and rejecting the concentrate is a common practice to remove these gangue minerals. However, sulphide minerals, such as chalcopyrite, can become naturally floatable due to surface oxidation and therefore may float together with naturally hydrophobic gangue. In this study, a new approach was developed to maximize the prefloat of hydrophobic gangue while minimizing the loss of sulphide minerals. The new approach introduced a prefloat cleaner stage where sulphide minerals recovered to the prefloat concentrate was depressed and separated from other hydrophobic gangue minerals at a low pulp potential with the prefloat cleaner tailing fed back to the main sulphide flotation circuit. Flotation tests were conducted using chalcopyrite and organic carbon. The results show that the proposed approach can significantly reduce the loss of valuable minerals in the prefloat flotation without affecting the reject of naturally hydrophobic gangue. Applying pulp potential control at the prefloat cleaner flotation stage also reduces the consumption of reducing agents while minimizing the effect of reducing agents on downstream rougher flotation.

Nov 23, 2020

By Raphael Victor

The construction and modification of tunnels brings a requirement for precise measurement of convergence and divergence to safeguard the structure, maintain safety and provide the assurance needed to maintain efficient progress. Established methods include manual measurement using tape extensometers and automated methods using photogrammetry and automated total stations. Drawbacks include the need for frequent access, power supply, cabling, and cost. The paper describes how the development of reliable optical displacement sensors (ODS) has changed the landscape. ODS sensors are connected to a long-range wireless mesh communications network via a solar-powered gateway outside the tunnel, with data instantly transmitted to the internet. A sensor and its reflector target can be installed in 20 minutes and is maintenance free for a decade. Tunnel movement is measured to sub-millimeter precision with repeatability of ±0.15 mm. Integration of a triaxial tilt sensor allows slope distance to be converted to horizontal and vertical changes and allows rotational movement to be determined. Applications include new-build and long-term structural health monitoring. Case studies will be given, including the refurbishment of rail tunnels in Spain where the ODS measured movement during track lowering in a situation where no other automated system was considered viable.

Jun 13, 2023

By A. J. Kwitowski

Teleoperation is a technology that can provide significant health and safety improvements in mining, by relocating machine operators hundreds of meters away from the face area. The U. S. Bureau of Mines (USBM) has recently developed a teleoperation system for continuous mining and haulage equipment. This system features near-real-time closed-loop control. A prototype system was developed and demonstrated on the surface. This system could be used in thin-seam applications down to 914 mm. Details are provided on the developed teleoperation system, results of testing, and expected, future applications of this technology for improved safety.

Jan 1, 1994

By Jerry C. Tien

China?s remarkable levels of economic growth during the past three decades have lifted almost 300 million people out of poverty. This amazing achievement has placed an increasing demand on energy and minerals, especially coal, which supplies 68.7 percent of China?s energy (June 2011). It is estimated that China mined more than 3 Gt (3.3 billion st) of coal in 2010, three times as much when compared to merely 10 years earlier. Such an impressive achievement does not come without major costs ?? including concerns with mine safety and an increasing number of occupational illnesses due to fast growth. This article reports on one of the major safety concerns in China?s coal mining, dust and dust control practices, and known cases of caol worker?s pneumoconiosis affiliated with prolonged exposure to excessive coal dusts. The exact size of China?s mining industry is not known, but it is estimated the coal industry is at least five-million people strong, and the metal and nonmetals industry probably employs another three million people. To meet increasing energy demand, China mined more than 3.1 Gt (3.4 billion st) of coal in 2010 from its 15,000 plus coal operations1, most of which are small- to medium-sized operations with annual coal productions ranging from a few thousand tons to 300 kt (330,000 st). These small coal operations are typically in remote areas, inadequately engineered, poorly ventilated and still using rudimentary drilling and blasting mining methods employing antiquated mining equipment and, presenting safety concerns, i.e., methane and dust explosions.

Jan 1, 2011

By J. W. Motter

Currently, virtually all new electric power generation systems under construction are designed with natural gas as the primary fuel. Factors driving these construction decisions involve sustained low prices for natural gas, environ-mental (and consequent regulatory) risks associated with the use of coal for power generation, and relatively high costs of construction for conventional coal-fired power plants. Despite the unarguable abundance of coal in the US. and worldwide, a fundamental question arises: What will be the role of coal in electric power generation in the 21st century? Congress, recognizing the vital and strategic importance of preserving the coal option for electric power generation, authorized the Clean Coal Technology Program. This pro-gram, with original funding in excess of $2,500 million, is intended to promote the demonstration and commercialization of a new generation of clean, efficient coal-based energy technologies through collaboration and partnering with private industry. The two technologies being demonstrated under this program which are the key to the continued use of this nation's huge coal reserves are coal gasification and the pressurized fluid bed. Either or both of these technologies, coupled with a combined cycle will pro-vide the continuing future coal option, while responding to increasingly more restrictive environmental standards. Recent Congressional budget-cutting efforts, however, could threaten the effectiveness of that model program, and ultimately other subsequent government-industry collaboration.

Jan 1, 1996

By Jerry C. Tien

The rare earth elements (REEs) are a group of 17 chemical (metallic) elements. REEs are used widely in high-technology, clean-energy products as well as weapon systems. China's dominant position as a producer of over 95% of the world REEs output and the world's increasing reliance on REE products have highlighted concerns about the future availability of rare earths in recent years. This paper briefly reviews the REEs world reserves, production, consumption, the impact of our heavy reliance on REEs products and China's changing policies on REE export on world supply chain.

Jan 1, 2013

By Leon Y. Sadler

Equations which predict the unsteady-state response of the continuous froth flotation cell to changes in operating conditions are necessary for the rational design of an automatic flotation cell control system. Unfortunately application of automatic control to froth flotation separation equipment has lagged behind application to other types of separation equipment (for example distillation columns, absorbers, liquid-liquid extractors, etc). This may be due partly to the unavailability of suitable mathematical models for predicting the dynamics of continuous mechanical froth flotation cell. This paper presents the results of a comparison of four dynamic flotation models (in transfer function form) using the same set of unsteady-state continuous flotation data. One of the transfer functions tested has been presented previously in the literature (1), another (2) has been accepted for publication, and two are given here for the first time. In addition, data are presented which confirm earlier findings that the mixing in the rotor-stator type cell is nearly perfect. The specific purposes of this paper are to: (1) provide the automatic control systems designer with several alternative dynamic mathematical models of the continuous mechanical froth flotation cell (2) give some idea of the relative a¬bility of each model to predict unsteady-state behavior by fitting each model to the same set of experimental stimulus-response flotation data and (3) provide more insight into the macro-mechanisms prevailing in the continuous mechanical flotation cell. The dynamic models which are presented and tested here all relate the time variation of the concentration of a given floatable mineral in the tailings to a time-dependent disturbance in the same floatable mineral concentration in the feed to the flotation cell.

Jan 1, 1972

By Ray Nivens, Umit Turunc, Caroline Sui, Nick Morrison, Douglas Steiner

"In most copper mines and concentrators, mill water is continuously recovered and reused, with fresh water added to make up for losses. When mixed, these water chemistries can lead to severe scaling, especially in pipes, tanks and pumps on the mill water supply side, reducing flows and causing significant production losses.At KGHM Robinson Nevada Mining Company, increases in the fresh water addition ratios resulted in severe scaling problems and premature pump failures thereby jeopardizing plant production. What initially appeared to be a few isolated scaling events eventually unfolded into a recurring pattern of water supply-related production losses with increasing severity. Through completion of detailed root cause analysis, chemistry modeling, laboratory work, in-plant testing and system engineering, the mechanisms of scaling were identified and addressed.Advancements in fresh water addition practices and antiscalant application methods resulted in a stepwise reduction of the mill water scaling. Cost savings and production benefits were significant to the plant’s financial metrics.IntroductionThe production of mineral and metal concentrates using the flotation process requires large quantities of water. Flotation is utilized as the primary means for beneficiation with sulfide ores. Mined ores are crushed and ground into a slurry of 20-55% solids. For each ton of ore, 400-900 gallons of water1 are needed to supply the grinding mill. Additional water is needed in the flotation circuit as well. With many modern mills operating at2 11,000-165,000 tons/day, water supply volumes can be upwards of 3,000 gpm to 100,000 gpm of flow.For plants operating at or above capacity, disruptions and restrictions in water supply flow can have a direct impact on the production and recovery of the metal. Water supply flow can be limited for a wide variety of reasons but of interest are those limitations that are due to mineral scaling. Mineral scaling is the selective point precipitation of inorganic species above saturation concentrations. Precipitated species form flow-restricting deposits in the mill water system (tanks, pumps, pipe and valves), that will eventually impact water supply to the concentrator."

Jan 1, 2017

By K. Anim, C. Calderon-Arteaga

Located in Mojave, CA, The Soledad Mountain mine is an Open pit Heap-Leach gold Mine, which is operated by Golden Queen Mining Company LLC. under private capital. Open pit mining began in 2015 while full production was reached in 2016. The open pit mine feed a processing plant that can process more than 13K tons per day of ore which is sent to a heap leach pad. The Soledad Mountain project is a poly metallic deposit with Au and AG being recovered as payable metals. As the mine became bigger after moving to the east pit phases, Golden Queen was facing new challenges to control the production and accurately determine KPIs to improve/increase the production. To maximize returns and asset value, a new fleet management system (FMS) was adopted and implemented. The new FMS has enabled the mine to interconnect the different stages of the mining, as well as to recognize issues and implement the necessary corrections. With the associated increase in complexity in the process, the requirement of the ore control system to accurately predict ore feed characteristics is critical to maximizing metal recovery. Implementation of new daily and weekly plans were needed to ensure the ore delivery and meeting the tonnage goals, while allowed the equipment operators to better geolocate and to maximize the equipment production. These conditions alongside with Golden Queen’s drive to increase profitability and maximize net asset value has created challenges. These challenges are numerous and multifaceted. However, the ability to accurately route the material from the mine, is critical to site success and some of these challenges have been overcome by the adoption of the new FMS, the implementation of daily and weekly plans and upgrades in the ore control workflow. Examples of how the integration of the new systems allowed golden Queen to improve production strategy, are discussed in this article.

Mar 2, 2022

By Donald J. Hill

To be successful, every organization within the mining industry must involve itself in researching and evaluating methods of loss control. The appraisal and evaluation of accidents and injuries is required to determine the costs of loss producing practices and conditions. This involves all of an organizations disciplines that concern themselves with a more efficient and cost effective organization. To come to know the cost of your safety program or how much is expended yearly for each employee on safety; to know what your safety costs are per man-hour or per ton-produced; to know what the health, medical and compensation costs are for any given incident are just a few of the important facts and figures that the safety management of a given organization needs to know to operate in the mining industry today.

Jan 1, 1984