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By E. M. Frizzell

This paper addresses the use of the microcomputer programs BACKONE and BACKWEDG for an estimation of rock mass strength characteristics by back analysis of plane and wedge failures. The artificial support requirements are also determined by the programs PLANE2, BOLTPAT, and BOLTWEDG in terms of rock anchor installation angles, tensions, and installation patterns. These programs have been combined into a package called BACKPACK, which can be applied in open pit mines where some failures have already occurred.

Jan 1, 1988

By Anthony D. Songer, James E. Diekmann, Jarrett E. Carlson

Computer Aided Design (CAD) systems are currently recognized as a necessary tool for the management of projects. Currently, CAD is used for TBM and conveyor setups, concrete lift design and overall constructability reviews. Typically, such CAD models exist only in 2 dimensions. The advent of more powerful computers, enhanced CAD programs and after market animation packages provides tremendous potential to the Tunneling industry. In particular, effective application of these technologies enhances cost, time and quality in field operations.

Jan 1, 1997

By Cao Changlin, Gong Qian, Hu Jiexue

The thiosulfate, effects copper of concentrations of and ammonia ou the extractlon of gold from sulfide gold concentrate have been studied. The experimental results showed that it is possible to reduce thiosulfate concentration. Above 95% of gold extraction was obtained in O. 2M thiosulfate leaching solution in two hours under the suitable conditions. Therefore, the process of washing residue was simplified, the consumption of thiosulfate and the loss of thiosulfate carried were reduced. by washing residued.

Jan 1, 1992

By M. J. Virnig, J. M. W. Mackenzie, M. W. Johns

The properties of Henkel's Aurix® resin which uses a guanidine functionality to recover gold by ion exchange have been described in publications of the International Mineral Processing Congress and Randol International (1)(2). The purpose of this paper is to provide an update on the results of further testwork using Aurix®. Specifically, this paper presents the first results of resin in pulp testing, all the results previously reported were for testwork carried out using synthetic gold leach solutions.

Jan 1, 1995

By Alan M. Ritchie, Paul Miskelly

The 2-D code FIDHELM has been used to simulate conditions in piles of pyritic material with vertical dimensions of 20 to 70 m and a horizontal dimension of 500m. Those properties of the pile and its external environment (wind, temperature) important in determining the time and space dependence of sulfide oxidation, have been identified. A prescription to evaluate the overall sulfide oxidation rate in a pile of known volume but variable geometry has been developed.

Jan 1, 2000

By Innocent John Arinze, Chidubem Okwudiri Emedo

This contribution presents the first multi-scale geophysical investigation conducted in the Abakaliki and Obubra mining districts (AOMD), southeastern Nigeria, for the exploration of shallowly emplaced (< 50 m) massive sulfide and barite mineral deposits. Raw airborne magnetic data covering the AOMD was acquired and subjected to diverse enhancement routines to facilitate the identification of areas of subtle magnetic anomalies for subsequent ground truthing. The mineralization is mainly made up of galena, sphalerite, and barite. The contrasting physical properties between these minerals and their host rocks make resistivity, induced polarization (IP), spontaneous potential (SP), and magnetic methods ideal to study and delineate the mineralization and possibly locate the ore bodies. Wenner DC resistivity and IP data acquired along the same parallel traverses are inverted using Res2dinv to produce 2D tomography models of resistivity and chargeability. The resistivity and IP models were successful in delineating zones of sulfide and barite mineralization. The ground SP data collected along the same traverses as the resistivity and IP data were interpreted as line graphs. The 1D SP models show a number of central negative anomalies that could be related to sulfide mineralization. These anomalies show fair-to-good spatial continuity and are in close agreement with the result obtained in the resistivity and chargeability model. This study suggests the presence of exploitable mineral deposits in the AOMD and demonstrates the superior interpretative ability of combined geophysical methods over a single geophysical approach.

Oct 20, 2020

By C. L. Pillar

In many cases, substantial time may elapse between the exploration stage and a serious detailed planning stage which has the objective of putting a mineral property into production. This is always true where properties change ownership and new partners are brought in for joint venture situations. Such conditions make it imperative that the recording of complete and accurate geological data for the property is done during the active part of the exploration phase and accomplished by competent geologists and engineers. This work should not be left to helpers and technicians. Furthermore, it should not have to be redone years after the actual drilling was accomplished, when either those involved have parted company or those present have lost the touch and feel of their part of the exploration program and must rely on a memory sketchy in detail, at the best. All of this emphasizes the importance of thorough geological evaluation and reporting during the exploration program. To evaluate and comment on the application of geological data by a mine planning department, we must assume (1) that sufficient diamond drill holes have outlined the existence of a potentially economic ore deposit, and (2) that the next step is to obtain the required information to allow a detailed feasibility study. This paper will comment on: 1. what types of geological information are required, 2. how it can be obtained, and 3. comments on the application of this information by the mine planners.

Jan 1, 1973

By M. G. Papasotiriou

For our company, S&B Industrial Minerals S.A., restoration of areas which were mined and the effort for bringing up again a balance of nature is an important priority over the last 3 decades. The successful qualitative results of restoration works have delivered to nature over 1.700.000 m2 of surface after mining activity. Our fundamental method in order to achieve the best results for restoration of mined areas is the use of local plants (bush or tree type). Grass and herbs are installed by using the method of hydroseeding. Small trees and bushes are produced and they grow up at our fully owned Milos nursery and they are installed during winter when weather conditions are suitable. During the initial stages of restoration activities a great amount of surfaces, adequately shaped, are delivered by the mining department covered with top soil. These surfaces are suitable not only for the local nature community but also for a combination between natural and agricultural environment. The above fact was a great chance to create small horizontal agricultural cultivations as pilots inside the restored areas. At the beginning the agricultural items that could potentially be installed in these pilot areas were studied and examined analytically. The following agricultural items were finally qualified to be furthermore researched: 1) Vineyard (Vitis vinifera ) 2) Prickly pear (Opuntia ficus indica) 3) Jojoba (Simmonsia chinensis) 4) Olive tree (Olea europea)

Jan 1, 2007

By S. Hicks

This technical note describes an alternative procedure that can be used in linear programming calcula¬tions where the compliance limit of lbs S02/million Btu for the blending coal is subject to change. Dr. Mateer in his technical note titled "Coal blending for sulfur compliance" (ME, September 1994, p. 1103) defined an "excess sulfur" parameter that provides a valid constraint equation for a linear program optimization. The coals used by Dr. Mateer in his examples are shown in Table 1. To create the parameters for the constraint equa¬tions to blend to an SO2 content of 1.2 lbs S02/million Btu; the excess sulfur for Coal A was defined as Sulfur excess%o = 0.5 - 0.6-13,000/10,000 = -0.28 This equation was used to create the constraint equation -0.28A + 0.44B + 1.36C<- 0.0 Another way to create the parameters for the constraint equation is given below. In these equations: ? W is the total weight; ? A, B and C are the fractional proportions of each potential blend stocks; ? Sa, Sb and Sc represent the percent sulfur content of the blend stocks; ? Ha, Hb and He represent the calorific content of the blend stocks in Btu/lb; and ? H and S represent calorific and sulfur contents of the composite blend. The weight of blend to produce one million Btu is [ ]

Jan 1, 1997

In order to reach a large, untapped reserve of high-quality coal, D8 Cloverlick mine proposed to mine a corridor nearly 2,000 ft deep beneath the Benham Spur of Black Mountain, Kentucky’s highest peak. D8 Cloverlick mine was extracting the Owl seam, but the corridor’s route lay approximately 70 ft above century-old mine workings in the C–(Darby) seam. Adding to the concern, three serious coal bursts had recently occurred in nearby Owl seam workings.

Jan 7, 2020

The 18th annual American Mining Hall of Fame Awards Banquet sponsored by the Mining Foundation of the Southwest will be held on Saturday, Dec. 2, 2000 at The Westin La Paloma in Tucson, AZ. The 2000 inductee, guest of honor and featured speaker at the banquet will be Ronald C. Cambre, chairman and chief executive officer of Newmont Mining. He will be honored for his role in positioning Newmont as an innovative and key player in the gold mining industry.

Jan 1, 2000

By David Caiden, Geoffrey Fosbrook, Jaidev Sankar, Donald Phillips, Jon Hurt, Anil Parikh

This paper will cover the progress being made on Phase 1 of New York’s Second Avenue Subway line. It will include a description of construction progress on the first contract to be let, which consists of a 248 m (815 ft) long launch box, 3.9 km(2.4 miles) of TBM tunnels and a tunnel sump; the packaging strategy for the remaining work; and the progress through Final Design of the remaining packages, including the two large span rock cavern stations.

Jan 1, 2007

By J. Sanko

When faced with the task of designing a process control system the control engineer must consider the following: 1. The type of process to be controlled and the manner in which the process must be controlled (the algorithm). 2. The type of equipment to be used to implement the control system. 3. A means of describing the control system for use in the following areas: a. Project engineering. b. Procurement of the control system equipment. c. Plant startup. d. Operator training and reference.

Jan 1, 1981

By L. K. Bandyopadhyay, P. K. Mishra, S. K. Chaulya, R. S. Singh, A. Kumar, N. Tripathi, K. Mandal

A comprehensive field study has been carried out to measure the background air quality status and identify the air pollution sources from opencast mines around a heritage site in India. Air quality modeling has been carried out to envisage dust concentration due to the existing and closed mines in the region. The predicted total PM10 and PM2.5 levels at the selected receptor locations ranged from 86.39 to 194.89 and from 34.82 to 99.55 µg/m³, respectively.

Jan 12, 2022

By Kenneth A. Pietila

The thickening and dewatering characteristics of refuse slurries are as variable as the coal mining operations and preparation plants that create them. This paper discusses these characteristics based on field studies at a number of mine sites. The connection between bench and full scale performance is confirmed with the design, construction and operation of an integrated 18m (60 ft) diameter thickener and 2.5 meter belt filter press system in Western Kentucky. The data from this system are presented.

Jan 1, 1984

By Wolfram Schnabel

Recently Lurgi has succesfully commissioned Peru&apos;s first direct reduction rotary kiln at SIDERPERU?s Chimbote works. The order included comprehensive engineering services and supply of special equipment to modify three existing cement kilns according to the SL/RN process. The kilns were cut to 62m length and installed with a slope of 2.5%. A new heating system, including shell burners, was supplied and inlet and outlet ends of the kilns completely renewed. Figure 1 shows the kilns after modification.

Jan 1, 1981

By Monserrat Rebolledo, John L. Uhrie, Candice Simms

Jetti Resources has developed a catalyst which overcomes the passivation of primary sulfides, enhancing the heap leach recovery of copper from chalcopyrite. It is important to emphasize that heap leaching of copper sulfides, whether with or without the Jetti catalyst, is a biooxidative process. We have demonstrated the efficacy of Jetti’s technology in bioreactors, with a chalcopyrite-dominant porphyry ore. In the presence of Jetti’s technology, optimal bioleaching conditions significantly increase copper extraction by 2.6 times that of the baseline.

Feb 1, 2025

By D. H. Dvorak

Two pilot-scale biological reactor systems were installed to treat metal-contaminated water. The reactors consisted of barrels and tanks filled with spent mushroom compost, within which bacterial sulfate reduction became established. Concentrations of Fe, Zn, Mn, Ni, and Cd were lowered by over 95% as these metals were precipitated as insoluble sulfides by reaction with bacterially generated H2S. The chemistry of the reactor systems is examined, and opportunities for maximizing their metal-retaining and alkalinity-generating potentials are discussed.

Jan 1, 1991

By R. R. Klimpel

This paper discusses the effect of water chemistry, reagent type, and other environmental factors on the performance of sulfide mineral size reduction and froth flotation processes. Two specific problems will be discussed: 1) the importance of appropriately utilizing the electrochemical window that is created in the grinding process to enhance sulfide mineral recovery by froth flotation; and 2) the impact of steel grinding media versus autogenous grinding on the efficiency of sulfide mineral flotation with varying thiol collectors and water sources.

Jan 1, 1996

By D. W. Fuerstenau

The flotation behavior of quartz in the presence of alkyl ammonium acetates as a. function of alkyl chain length has been interpreted in terms of hemi-micelle formation at the solid-liquid interface. The van der Waals cohesive free energy that is responsible for hemi-micelle formation has been found from these results to be 1.02 kT per CH group. This 2 is in excellent agreement with literature values obtained from research on the properties of micelles in bulk systems.

Jan 1, 1964