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By Alexander Guzmán Y

"El presente trabajo es realizado con el objetivo de optimizar el proceso del método de explotación Sublevel Caving SLC en mina subterránea Yauricocha realizando una mejora continua. La mina Yauricocha tiene como principal método de explotación el Sublevel Caving SLC aportando el 87% del total producción mina."

Sep 1, 2017

By Woodcock J. T

A sulphide ion selective electrode (ISE) is suitable for control of sodium sulphide additions in flotation because it has a rapid response to changeS in S2- concentrations, can indicate -low concentrations at differentpH values, suffers from few interferences, and is robust enou'gh to use in a pulp. Three sulphidization techniques were studied using the lSE electrode for measurement and/or control of S2- levels. Metallurgy was assessedfrom concentrate grades and copper recovery.With slug additions of sodium sulphide, sulphidizing conditions were poorly defined and reproducibility tended to be poor. Although acceptable metallurgy could be achieved by multiple additions, sodium sulphide consumption was high.Controlled potential sulphidization readily gave good metallurgy. The optimum potential of the lSE for sulphidizing was about -500 mV versus SCE, but depended on sulphidization and flotation times; suitable times were3 and 5 min respectively for three to five stages. Application of this technique to previously untested ores gave good metallurgy in a first test in spite of variation by a factor of three in the sodium sulphide requirements ofthe ores.Simultaneous sulphidization and flotation was satisfactory when conducted at an lSE potential of -450 mV versus SCE. Mixed cha!copyrite-oxide copper ores responded satisfactorily.Besides optimizing sulphidization conditions it is also necessary to optimize xanthate additions (e.g. by measuring xanthate residuals).

Jan 1, 1978

By Jae-Hyung Park

Since the Industrial Revolution, the land resources have been decreased rapidly as the industrialization. And this phenomenon brings to our mind an interest in deep-sea resource(manganese nodule). Hence, Korea has been participated in the development project of exploiting manganese nodule since 1983. Hwang and cho(1998) studied the economic efficiency evaluation of manganese nodule carrier. But they used the TAMU(Texas A&M University) model, and assumed deadweight and velocity of bulk-carrier. If we use some optimization technique, more economic manganese nodule carrier can be selected and evaluated without limited assumption. In this study, we evaluated the economic efficiency of manganese nodule carrier using genetic algorithms(GAs).

Jan 1, 2003

By S. Sagar

In September 1996, Dofasco commissioned a 165 Mt twin shell EAF furnace and an associated ladle fleet. During and after this startup, refractory performance in the ladles was optimized on a holistic approach through several initiatives that increased ladle refractory retention times from 7000 to over 16000 mins (160 heats). This dropped the overall refractory costs by 40% while ensuring a consistent and predictable ladle performance. One initiative that drove enhancements was the proper brick selection for each particular refractory area and it's process conditions. The work concentrated on the selection of a resin bonded alumina magnesia carbon (AMC) brick in the barrel area of the ladle, upgrades to the 2 piece monolithic alumina cast ladle bottom and increasing the slagline refractory brick quality with the appropriate zoning/paneling. The adoption of a magnesia alumina carbon (MAC) brick in the transition area of the barrel/slagline has also improved performance and predictability. The design developments have lowered the overall wear rates and balanced the service life of the entire ladle. Safety was improved and breakout potential reduced by changing the safety lining from a high alumina brick to a state of art technology - monolithic shotcrete lining. This initiative decreased the overall manpower required to brick a ladle and increased shop ladle availability. The ladle bricking area environment was also improved by adopting a post combustion device to burn phenol fumes from ladle preheating practices. This has improved the overall health & safety of the reline teams. The consistent and predictable performance of the ladle on a whole has allowed the shop to decrease the number of working ladles in operation from 5 to 4. This further decreased wear rates from over-oxidation and excessive thermal cycling, saving approximately $500,000 in natural gas from pre-heater operations.

Jan 1, 2004

By Alexandra Kozak, Rodrigo Costa, Bob Fukuhara

"The Jacobina project in Bahia, Brazil commenced operations in 2004 with a design capacity of 4,200 tpd. A project development plan to increase plant capacity to 6,500 tpd will be discussed. The project included an evaluation of the existing circuit and addressed bottlenecks in the crushing, milling, sedimentation, leaching and tailings transport. These circuits and the methodology used to provide higher capacity will be presented.INTRODUCTIONThe Jacobina mine is located in the state of Bahia in northeastern Brazil approximately 330 km northwest of the state capital city of Salvador and 9 km from the town of Jacobina. The Jacobina Mine (Figure 1) is owned by Jacobina Mineração e Comércio, a wholly owned subsidiary of Yamana Gold Inc.The gold mineralization of the Jacobina mine is hosted within quartz pebble conglomerate reefs of the Serra do Córrego Formation which together with the Rio do Ouro Formation forms the Serra do Jacobina mountain chain.The Serra do Jacobina mountains have been mined for gold since the late 17th century. Since the 1970’s, the Jacobina mine has been operated by Anglo American, Williams Resources Inc., Desert Sun Mining Inc. The mine is currently owned by Yamana Gold Inc.In December of 1998, operations at Jacobina were suspended and the property was placed under care and maintenance. Desert Sun Mining Inc. began exploring the property in 2002 and eventually purchased the Jacobina mine in 2003. In 2003, a feasibility study was completed that evaluated the economics of re-developing the mining operations and expanding gold production. In 2004, refurbishment and re-development of the mining operations began and the milling facility throughput capacity was expanded from 1.08 to 1.512 Mtpy (3,000 to 4,200 tpd). The milling operations were commissioned in the 1st quarter of 2005 and commercial production was declared 1 July 2005. In April 2006, Yamana Gold Inc. acquired the Jacobina mine through its acquisition of Desert Sun Mining Inc."

Jan 1, 2008

By R. Costa, A. Kozak, B. Fukuhara

Introduction The Jacobina mine is located in the state of Bahia in northeastern Brazil approximately 330 km northwest of the state capital city of Salvador and 9 km from the town of Jacobina. The Jacobina Mine (Figure 1) is owned by Jacobina Mineração e Comércio, a wholly owned subsidiary of Yamana Gold Inc. The gold mineralization of the Jacobina mine is hosted within quartz pebble conglomerate reefs of the Serra do Córrego Formation which together with the Rio do Ouro Formation forms the Serra do Jacobina mountain chain. The Serra do Jacobina mountains have been mined for gold since the late 17th century. Since the 1970’s, the Jacobina mined has been operated by Anglo American, Williams Resources Inc., Desert Sun Mining Inc. and now Yamana Gold Inc.

Jan 1, 2007

By Xiancong Zhao, Hao Bai, Qi Shi, Zhancheng Guo

Reducing electricity cost is important for energy intensive industries such as the iron and steel industry. With the implementation of time-of-use (TOU) electricity price, plenty of attention has been paid to the optimal management of byproduct gases. The time-of-use (TOU) electricity price is the practice of implementing different prices for different times of use. It is possible to reduce electricity cost by adjusting the amount of product gases stored or used for power generation throughout the day. In this paper, a novel mixed integer linear programming (MILP) model concerning the TOU electricity price is proposed to optimize byproduct gas use. Compared with previous models, this model considers the optimal load shift between gasholders and boilers under TOU electricity price. The case study of a steel plant demonstrates that the electricity purchase cost can be reduced by more than 30% after optimization.

Jan 1, 2016

By D. Moradkhani

Copper metal has important role in the basic industrials, as if it did not exist, modern human life would not develop! Copper leaching, as the first step, is important step in copper production processes. In this research, efficient factors on the leaching have been investigated. For this reason, four efficient factors on leaching namely pH, liquid to solid ratio (L/S), temperature and time, as independent variables, were optimized using response surface (RSM) with D-optimal. A quadratic equation was used to create response and contours. According to the results from analysis of variance (ANOVA), the value of determination coefficient (R2=96.77%) indicates that the model was good fit. Optimum experiment condition also was found: pH of 1, L/S of 8.24, temperature of 26.06 ? and time of 43.64 min. At this condition, the maximum recovery of copper was equaled to 92/38 in which good desirability achieved.

Sep 1, 2012

By Mike D. Adams

Testwork was conducted on loaded carbon samples from a small gold mine in South Africa. It was shown that a 75% saving in reagent consumption in the Zadra elution circuit could be achieved by adopting a cyanide-free elution approach, i.e. by cutting back the NaCN level from 1 % to nil, and the NaOH level from 3% to 1 %. This process change was also shown to result in a 20% improvement in the elution kinetics. Furthermore, it was also shown that a 50% enhancement in elution rate over the current situation could be achieved by use of an eluant containing 0.5% NaOH and 0.15% NaCN, corresponding to an 84% saving in reagent consumption. A further improvement in elution kinetics was found to occur by increasing the NaCN level to 3%, but this would lead to a concomitant increase in reagent consumption, due to the decomposition of cyanide at high temperatures. The presence of base metals loaded onto the carbon was also found to have a significant effect on the elution. Copper tends to adsorb as Cu(CN)2- during the adsorption stage, and acid washing converts this species to CuCN. Copper in this form is not eluted during cyanide-free elution, whereas it is eluted during a conventional cyanide elution, consuming the initial cyanide in the process. The elution data was analysed and the fit to a simple model was verified.

Jan 1, 1995

By Jorge Cárdenas, Alejandro Luna

In mining simulation for fragmentation results prediction is of utmost importance to study feasibility, ensure safety, and estimate the correct use of resources in drilling an explosive to meet requirements and avoid excessive usage. One critical case is fragmentation prediction, developed through models. Developing a fragmentation model in a mining unit aims to control blasting results to align theoretical and real data and improve correlation. Therefore, it is essential to collect post-blast fragmentation data, organize it, and systematically process it to develop a suitable model that meets variable requirements. Using a robust system of equations, this model should generate the required results with minimal variability between simulation and actual results. Additionally, this model must be adaptive to reduce this variability. Studying the most known and used models in mining resulted in our work correlating Cunningham 2006, Swebrec, and CZM models. Thus, the Simfrag model was created, presenting a robust foundation and combining the most notable advantages of the aforementioned models.

Jan 21, 2025

By S. Yang

Based on an analysis of the features found in Chinese surface coal-mining areas, including areas that have already been developed and areas that are in the process of being developed, this paper discusses some rational coal-haulage systems. An optimal decision-making model, which includes a geological model, a mining model and an economic estima¬tion model, was developed for the selection of a coal-haulage system. A case study is presented.

Jan 1, 2000

By V. Srajer

Several optimization approaches used by the Canadian mining industry were used to investigate surface coal mining operations in Canada. A computer program was applied to optimize truck/shovel systems and for various analyses. The analyses of eight western Canadian coal mines included investigation of fleet imbalance, under- and over trucking, development of the criteria for automated truck control, comparison study of various haulers and loaders, haulage layout, driving conditions, machine performance, servicing and maintenance policies, etc. Each property investigated supplied background information for the study and cooperated in optimization studies. The truck/shovel system optimization study is demonstrated as a test case to outline procedures and step-by-step instruction for similar applications.

Jan 1, 1989

By Q. X. Yun

This paper presents a new approach to optimize the transportation system in open-pit mines. The new approach employs artificial intelligence, fuzzy sets, dynamic programming and CAD technique to determine the transportation system. The determination consists of 4 phases: initial selection, road alignment, final decision .and open-pit drawing.

Jan 1, 1992

By A. L. Mular

Optimization strategies of possible interest to mineral processing are reviewed and typical strategies initiated in processing plants to date are discussed. Both On-Line and Off- Line optimization procedures have been employed by industry, assisted either by operators or by digital computers. In every case, dollar benefits have accrued.

Jan 1, 1976

By E. Woodburn, R. Putman, A. L. Mular

Optimization strategies of possible interest to mineral processing are reviewed and typical strategies initiated in processing plants to date are discussed. Both On-Line and Off- Line optimization procedures have been employed by industry, assisted either by operators or by digital computers. In every case, dollar benefits have accrued.

Jan 1, 1976

By H. S. Rathor

NTPC (National Thermal Power Corporation), a multi-unit organization, is generating 26% of India’s total power. This power is produced from its 14 coal based stations and 7 gas based stations. NTPC is entering into the business of power-distribution, power-trading, setting up of coal mines and diversification in non-conventional energy sector as well. For achieving the goal of the country “Power for All” NTPC has taken a giant stride by entering into Hydro Power generation which is also the cheapest and the cleanest renewable source of energy. In its pursuit for excellence, 800 MW Koldam Hydro Power Project is NTPC’s first venture in hydro sector. In Koldam, hydropower potential will be harnessed by constructing a 163m high earth and rock fill dam in a narrow gorge at upstream end of Bhakra reservoir. The river diversion is envisaged through two parallel, 14m finished diameter ‘horseshoe’ tunnels of length 901m and 934m at village Kian on the right bank, where the river forms a 180° loop. The diversion tunnels are designed to accommodate a flood of 6500m3/sec, taking into account the maximum probable discharge of 200 years return period. The tunnels pass through dolomite and limestone rock formations. The excavation of tunnels was done with drill and blast method. The excavation was attempted from both inlet and outlet faces. During geological investigation a rock fault was located at the outlet area. The location of the fault was such that it was passing through the edge of the Tunnel-1portal and around 30m away from the face of the Tunnel-2 portal. The quality of the rock at Inlet was also poor. To save the portals from slips, excavation of the tunnels was planned to start after the completion of the open excavation and its support system both at inlet and outlet. The tunnel excavation at inlet was envisaged by approaching the tunnels’ portal by constructing a road through 540EL bench and meeting the inlet portals on the upstream end, which would have been ready by mid2003, only after completion of the open excavation and its support system. To save time and cost, it was felt necessary to modify the planning by starting the tunnel excavation simultaneously along with open works both at inlet and outlet. The excavation at the inlet face of the tunnels started in December 2002 after rerouting the approach road to inlet portals through haulage road on the downstream and similarly Tunnel-1 at the outlet was started in the low cover area before completion of open area works. Thus the tunnel—heading excavation was started nearly 06 months early with the change of methodology.

Jan 1, 2005

By Beatrice Pierre, Juan Carrasco

Altonorte began as a concentrate roasting operation in 1988 under the name of Refimet. In 1993, a copper smelter was built with a design capacity of 203,000 tonnes per annum of concentrate. Since 2001, many technological advances have been made in Altonorte, where the biggest Noranda Reactor in the world is installed being the first Noranda Reactor reaching above one million tonnes of copper concentrates processed per annum. In 2013, Altonorte was acquired by Glencore. Recently due to various new environmental regulations in Chile, Altonorte has evolved to new standards of operation in order to reach the vision of becoming a World Class Smelter. This paper describes the path followed to improve safety, environmental performance, process capacity, reliability, and productivity. The foundation for the growth and success in Altonorte is our People. Employee engagement and branding of our cultural journey is what allows Altonorte to face the future with the certainty of becoming a World Class Smelter. INTRODUCTION Altonorte is located in Antofagasta, the mining capital in the north of Chile and is the last smelter built in Chile practically completed with second hand equipment. The biggest technological change in Altonorte occurred during the phase 3 expansion in 2003, where the old Reverberatory furnace was shut down and replaced by the biggest Noranda Reactor installed in the world. The vessel measures 5.3 m × 26m. ºAdditionally, this project contemplated a new rotary dryer, three (3) new Peirce Smith converters, new anode furnaces and a new Acid plant. The nominal capacity was to treat 816.000 tons of new concentrate per year. In 2008, a new expansion phase was implemented where a new double absorption acid plant replaced the oldest acid plant. Bottlenecks such as blowing capacity and oxygen availability were solved installing a new air blower and a new contract was negotiated with our oxygen supplier to increase oxygen availability up to 683 tpd. This improvement defined the current nominal capacity of 1.100.000 ton of new concentrate per year. Current process description All concentrates are received by trucks directly from domestic mines or from the Antofagasta international port in cases of imported concentrates; the concentrate warehouse has a capacity of 25 kt where the blend is prepared to feed the smelter.

Jan 1, 2019

By Tiejun Chun, Gutian Mu, Jiaxin Li, Hongming Long, Zhengwei Yu, Ning Li

The basic characteristics of iron ore, including assimilation, fluidity, cohesive phase strength and the ability to produce calcium ferrite, are often used to evaluate the sintering properties of iron ore and guide the optimization of iron ore blending. Six kinds of common iron ore used in a steel company in China were selected in this work. The basic characteristics of the single iron ore and blended iron ores were studied, as well as the difference between weighted averages of basic characteristic index of single iron ores and the real value of basic characteristic index of blended iron ore under different ore blending ratios. The results shew that the liquid phase liquidity, cohesive phase strength and calcium ferrite formation ability had a significant linear positive correlation with SiO2 content. The weighted average of basic characteristic index of single iron ore cannot fully reflect the actual blended iron ore properties. The optimization of the blending ratio can be achieved through the detection of the basic characteristics of the mixed iron ore, combined with the basic characteristics of iron ores.

Mar 1, 2018

By J. Changsheng, Z. Youdi

Based on the criteria of maximum net present value per ton of reserves and on the optimum matching of some other essential parameters, a comprehensive optimization model of surface-mine production rate is developed using system- engineering approaches and using the theory of economy of scale. A mine is then selected to demonstrate the application of the model.

Jan 1, 2000

By Sizhe Tan

An open pit mining operation can be considered as a production system with at least two products: ore and overburden (waste). A primary mine planning task is to schedule the production of ore and waste over its life span subject to several technical and economic constraints to maximize some objective such as the overall profit from the operation. Two major constraints are (i) the feasible combinations of ore and waste productions and (ii) the limiting function for ore production as a function of mine life. The task in scheduling production and stripping ratio (ratio of waste to ore production) is to find an ore production curve below the upper bound function of ore production, and a stripping ratio curve within the feasible domain of ore production and overburden removal while maximizing the defined objective. Zn this paper, feasibility of developing computerized optimization models to perform such a scheduling process is explored. Two optimization models are proposed for the task. In the first approach, a linear programming (LP) model is employed and in the second, a dynamic programming procedure (DP) is outlined. In these models, in addition to the consideration of the two major constraints mentioned earlier, various other contributing factors such as interest rate, equipment purchase cost and installation schedule, operating cost, and equipment idle cost are incorporated. An example is provided to illustrate the LP model application.

Jan 1, 1992