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By J. Castaneda, J. Schmidt

"INTRODUCTION Chino is an open-pit copper mining complex faced with intricate material routing requirements. Historically, this was challenging at the mine, in part because the shovel dig plan, haul plan, and dump plan were prepared completely separately. The mine now uses an integrated workflow for faster evaluation of schedules, which facilitates preparing balanced cutoff grade-to-equipment requirements, supports better mineral production, and improves schedule viability, while considering operational implications. Located in the state of New Mexico, Chino is one of nine Freeport-McMoRan mining operations in North America. This presentation discusses the benefits of implementing an integrated approach to tactical mine planning, and shares practical examples that were learned as Chino implemented an integrated tactical planning method. This includes improvements in completion time for preparing a schedule, minimal risk from manipulating Excel macros, data integration required to make short-term planning decisions, and better understanding of the mine plan’s effect in relation to the business’s key performance indicators. Ultimately, the integrated approach to tactical mine planning at Chino has led to production forecasts which are more achievable and reduced planning and execution variance. PROJECT OVERVIEW Chino mine is a porphyry copper deposit wholly owned by Freeport-McMoRan, the largest publicly traded copper producer in the world. Chino mine is located in Grant County, New Mexico, a short distance east of Silver City. Ore material mined from the pit today includes oxides, primary sulfides, and secondary sulfides. The mineralized material is sent to a mill, with a rated throughput of 42,000 tons per day, or to ROM leach pads with variable dumping capacities. At Chino, the short-range objective is to maximize total copper pounds sent to the mill, but no fixed cutoff grade accomplishes this for all periods. Instead, 12 different material classifications, including four sulfide classes that can feed either the mill or other destinations, and 38 cutoff bins, are aligned with the needs from operations, leaching, and the concentrator to create a schedule. Cutoffs vary from one week to another to cope with a highly intermittent ore body."

Jan 1, 2018

By Donald Towse

The Permanente plant of Kaiser Cement & Gypsum Corporation is located at a unique thick deposit of Calera Limestone (Figure 1) on the southwest side of San Francisco Bay. Limestone is rare in the eugeosynclinal Franciscan assemblage, constituting less than 0.1 percent of the total volume. On the northwest part of the San Francisco peninsula Calera Limestone is present as isolated masses from the type sect ion near Rockaway Beach southeastward for ten miles, where the belt is truncated by the San Andreas fault. The large Permanente deposit is sixteen miles south of the truncated belt, on the northeast side of the San Andreas fault. Scattered small exposures are known for about twenty miles southeasterly from Permanente. (1,2) Most deposits of Calera are thin; the type section is about two hundred feet thick. At Permanente, however, the normal limestone section contains at least four hundred feet of limestone; and, due to folding and extensive faulting, the total vertical thickness of the limestone section is over 1400 feet. The unusual thickness of limestone is due to low angle thrust faulting. This fortuitous structure formed a deposit of limestone that supplies an 8,500,000 barrel cement plant in a major metropolitan market.

Jan 1, 1966

By Tetsuji Hirato, A. J. Monhemius, Yasuhiro Awakura, G. W. Warren, E. Peters

An electrostatic pseudo-liquid membrane technique, in which extraction and stripping take place simultaneously in a single reaction vessel using an electrostatic dispersion, was applied to recover Ni(II) from aqueous 0.1 kg m-3 Ni(II)(as NiSO4) – CH3COONa solutions, and the Ni(II) ions were concentrated by a factor of 9 into an aqueous 1.0 kmol m-3 HCI solution using D2EHPA as an extractant at the applied voltage of 3.7 kV for the dispersion. When the process of ESPLIM proceeds favorably, the concentration of Ni(II) in the upper part of the organic phase of the reaction vessel is lower than that in the lower part. In addition, the concentration of Ni(II) in the organic phase of the extraction chamber is higher than that in the stripping chamber. For the stable operation of this process, the stripping rate must be greater than the extraction rate to prevent the excess accumulation of Ni(II) in the organic phase which leads to the poor dispersion of the aqueous phase.

Jan 1, 1993

By Igor Gonzales G.

Southern Peru Copper Corporation (SPCC) has recently completed the construction of copper leaching, solvent extraction, and electrowinning facilities at their Toquepala and Cuajone plants in Southern Peru. Much of the ore for these new operations is the result of the existing mining operations that have been in existence as early as 1959. At Toquepala, pre-conditioning and bacterial dump leaching of the sulfide ore that was too low in copper content to be processed through the copper concentrator began in 1987. The Cuajone heap leach operation is treating copper oxide ore that has been stockpiled since the Cuajone concentrator began operation in 1976. The pregnant leach solutions from the dump leaching at Toquepala and the permanent pad heap at Cuajone are combined into one plant feed solution. Adjacent to the large dumps at Toquepala, a solvent extraction and electrowinning facility has been constructed. The electrowinning facility has a planned annual production rate of35,000 metric tons per year Grade A cathode copper. Initial production of the cathode copper began in November 1995.

Jan 1, 1996

By George H. Tousley

As a member of the vast fraternity of those that supply and service the mining industry, I can assure you that we are amused, amazed, and horrified at the poor drilling and blasting practices of a great number of operations. Yes, ?horrified?. After all, that is our product you are using and abusing. We all know that drilling and blasting is expensive. In some operations D & B costs may exceed excavating or hauling costs, or both. At any rate, it is the only portion of the whole operation that could be said to directly affect other costs. There is no argument that it affects excavating costs. If the overburden and/or product is drilled and hauled, it affects haulage costs. It can easily affect milling costs, if more or less fines is important. And poor fragmentation affects crushing costs. If scalping is done ahead of the primary crusher it can affect production. As has been pointed out, the D & B operation itself is costly, and therefore should lend itself to close scrutiny. Anyone that could immediately decrease haulage costs by 10% would be a hero with any mining company.

Jan 1, 1976

By Jr. Koch

Since 1882, world zinc production has increased. In contrast, United States zinc production rose until about 1915, but since then has remained nearly constant, with a slight tendency to decrease. Production from the Tri-State district, the largest early source of zinc in the United States, has gone down steadily; this decline has been balanced by a growth in the rate of other districts. These changes in United States production are due to economic, not geological, factors. Recent exploration has located large mineable ore bodies; additional deposits will undoubtedly be found in the strata-bound carbonate rock and volcanogenic environments. A statistical analysis of the exploration effort in the Middle Tennessee district indicates that new discoveries can be expected there. Thus, the United States is in an early stage of the production cycle for zinc. Of major mining districts in the United States, only the Tri-State is exhausted under current economic conditions; large zinc resources of low-grade material, which would repay mining at higher prices or improved technology, are known to exist in that district.

Jan 1, 1980

By P. L. Sibrell

Previous research by the U.S. Bureau of Mines showed that autoclave cyanide leaching of used automobile exhaust catalysts for recovery of platinum group metals (PGM) was technically feasible. This work involves a more detailed investigation of the chemistry of the dissolution of PGM in cyanide solutions. The PGM species in solution identified by ultraviolet spectroscopy. Pt and Pd cyanide complexes were square were The planar in geometry, while the Rh complex was octahedral. The rate of dissolution of the PGM was also investigated using a rotating disk technique. Dissolution rates increased in the order of Rh, pt, and Pd, respectively.

Jan 1, 1994

By R. W. M. Lai

The study of flotation kinetics was first reported by Garcia-Zuniga1 in 1935. Since then, literature on the subject has grown with the time. 2-19 Although there is an abundance of flotation kinet¬ics models available in the literature to describe flo¬tation systems, they are mostly of academic interest and are seldom applicable for use in the industrial environment. Several reasons contribute to the wide gap in the industrial -application of the academic models. These include: 1) the lack of generality in the model, e.g., the model is limited to certain size ranges; 14 2) the academic models involve complicated mathematics; 5,6,10,11 3) confusion about the order of the flo¬tation rate, e.g., several authors proposed a first order rate model, 1,15,16 whereas the others propagated a second order rate model: 2,17,18,194) the use of an unrealistic rigid value, such as the use of a maximum recovery of 100%, 5,8,19 which is unrealistic in industrial operations; and 5) the use of graphs that confuse the reader rather than interpret information. 2,3,10 This paper intends to introduce a simple and easy to understand empirical flotation kinetics model along with a way of presenting the model in an informative graphical form, which should stimulate the interest of other practical engineers to become concerned with practical application within the mineral industry.

Jan 1, 1982

By Ian Graham

In 2013 the Government of New Zealand launched a number of ‘National Science Challenges’ (NSC) to address major issues facing the nation, and raise public consciousness about science and its role in promoting evidence-based decision making. One of the 10 proposed NSCs focuses on New Zealand’s extensive Exclusive Economic Zone (EEZ) and Extended Continental Shelf (ECS)1, with an objective to enhance utilisation of marine resources within environmental and biological constraints, and the desired outcome of:

Sep 1, 2014

By Edward M. Downs

This paper is a brief review of the lubrication requirements of enclosed gearing on earth moving equipment, particularly as they apply to intermediate and large draglines and shovels used in open pit mining operations. It discusses the requirements of spur, helical and herringbone gearing in both horizontal and vertically mounted applications. The effects of base stock, oil viscosity, additive treatment, quantity of oil and method of application are considered. In addition, a newly designed circulating oil system for enclosed swing gear cases and the reasons for its development are discussed.

Jan 1, 1968

By G. Reed Marchant

The control systems engineer is often faced with the problem of designing tests or experiments where the cost of obtaining information is expensive. This is true in aerospace as well as in process industries. In these situations the details of test design should be carefully evaluated before any test is executed so that the maximum amount of information is obtained for the effort expended. In recent years there has been a steady trend towards increased automation, In the process industries this has resulted in extensive review of process variables and, instrumentation techniques, development of more accurate system mathematical models, and extensive investments in complex control system as well as completely automated plants. When planning and developing these systems, where each measure of a process variable is usually expensive, it behooves the design engineer to give considerable thought to the details of test design before instrumentation is procured and installed so that the maximum amount of information can be obtained for the expense incurred.

Jan 1, 1968

By C. B. Kettering

In the early operations of the Inspiration Consolidated Copper Company, which extended from 1914 to 1926, the ore as mined contained principally sulphide copper minerals, manly chalcocite (Cu2S), This ore was milled in a 20,000-ton concentrator and the copper was recovered as a flotation concentrate which, was smelted at the nearby plant of the I ternational Smelting and Refining Company. In those days no attempt was made torecovercopper from any oxide minerals present. As mining operations progressed it soon became evident that the proportion of oxide minerals present would steadily increase, and. it was realized that some method of treatment would have to be developed whereby copper could' be recovered from both oxide and. sulphide minerals contained in the ore. A research program was instituted and after some years of experimental and, pilot plant work a new hydro-metallurgical process was developed whereby it became possible to extract copper from both the oxide and. sulphide minerals in a single leaching operation. The solvent adopted consisted of a mixture of sulphuric acid and ferric sulphate,' Following dissolution, the dissolved copper would be recovered by electrolysis. Also in the process of electrolyzing, spent solutions of sulphuric acid, H2SO4, and. ferric sulphate, Fe2(SOk)3, would be regeneratede and. somade available for continuous reuse. The process appeared to be a success and the decision was made to build a full-sized leaching plant for the future treatment of I spiration mixed ore. Construction was started and the leaching plant was completed in 1926, With the start of ferric-sulphate leaching the Inspiration Concentrator was shut down and, with the exception of a few short time runs has not operated since that time. The ferric sulphate leaching process served. Inspiration well for some 30 years and during that time won a name for itself as a classic example of hydro-metallurgical treatment of mixed sulphide oxide ores. Originally the plant was designed. to process some 7,500 tons per day of a mixed ore containing about 1,2% copper, of which 60% was present as oxide and. 40% as sulphide, Down through the years various improvements were made for the purpose of increasing plant capacity and as well to change the limiting 'factor of sulphide-oxide ratio, The final result was a leaching capacity of 9,600 tons per day when treating a 1% copper ore with a reversal of the sulphide-oxide ratio to 60% sulphide and 40% oxide.

Jan 1, 1958

By Karl J. Benecke

Though the first patent on a bucket wheel excavator was granted in 1881 in the U.S. this technology was developed in Germany to the high standards of today. However, this development was only possible in parallel with the development of shiftable belt conveyors and boom stackers. The combination of these three types of equipment in the open pits of the Federal Republic of Germany has made lignite the cheapest energy source for power generating, despite the low heating value of German lignite in the order of 8500 kJ/kg (3600 BTU/lb) only. Comparing the costs for fuels used in power generating on the basis of their heating value, the relation between lignite, high quality black coal, and imported crude oil is in the order of 1 to 1.5 to 2.5, hence highly in favour of lignite. These cost advantages for lignite in Germany are due mainly to the concentration of lignite mining in a few high-output open pit mines. The largest one, Fortuna Mine in the Cologne district, produced a, total of 45 000 000 t lignite in 1976. That equals the annual fuel need of a 5750 MW power plant running 7000 hours per year at full capacity. Altogether 95 200 000 bank m3 equal to 200 000 000 t overburden had to be removed to accomplish this lignite output. The largest BWE (Fig. 1) ever built is working in the Fortuna Mine, too. At a digging height of 51 m above crawler level, the total vertical reach in relation to the face conveyor level is 98 m by means of its conveying bridge and loading unit. The hourly output is 10 400 bank m3. Its weight in operation is 13 000 t, its wheel diameter 21.6 m, as high as a 7-storey building.

Jan 1, 1977

By R. Bhaskar

The control of respirable dust in mines has been given paramount importance due to the health and safety implications associated with fine dust. The understanding of the temporal and spatial behavior of dust has been recognized as essential for increasing the efficiencies of the existing control techniques and for developing new control strategies. Mining-related studies in this area are, in general, limited. They are also mostly experimental. Some mathematical and computer analyses have been attempted. In this paper, first a review of the mathematical studies performed in the last three decades in this area is presented. Second, a mathematical model for analyzing dust flow in mines is proposed. The model takes into account a number of factors affecting dust transport. It incorporates varying dust generation source strengths and dispersion, deposition, and coagulation of dust in mine airways. Finally, application areas for the model are discussed. A computer program based on the mathematical model has been developed. The program will output the dust concentration in the mine atmosphere as a function of time and distance from the source. The amount of dust deposited on the sides, roof, and floor of the airway is also determined.

Jan 1, 1985

By D. V. Bush

There has been a great deal of evaluation and discussion on the economics of semi- autogenous grinding versus conventional grinding circuits. This paper will not discuss the merits of one system over the other, but rather will discuss the Henderson Mill's approach toward achieving the most economical milling conditions in its existing SAG mills.

Jan 1, 1985

By Donald M. Ulbrich

Any of you who served in the military remember the admoniton to "get the lead out," In the military environment, where cost wasn't always a factor, "get the lead out" was more often a call for activity of any sort than activity of a particularly productive nature. As a result, when the top sergeant yelled "get the lead out," lots of people started moving.. . usually to get out of his way. Now there's a new cry, ..one that comes not only from the military but from an entire nation threatened with dependence on foreign sources for its energy needs. That cry ...get the coal out, Like the earlier order, it's a call to activity. A signal that the coal reserves of the United States must be tapped so that Project Independence can succeed by 1985, But it's more than a mere call to activity; it's also a call to achieve productivity. ,a call to produce coal both efficiently and acceptably. And that leads us to the key questions of where the coal is going to come from to meet that 1985 goal, and how can it best be mined. Where will the coal come from? There's no doubt much of it must come from surface mining in the West. How can this coal be mined? There are several options available but there is an excellent case to be made for using mining shovels and haul trucks due to their versatility in stripping, loading and reclamation, We'll explore this approach in this talk today.

Jan 1, 1976

By John Bailey

Stressmap is a program whereby the earth's stress field is charted in detail and utilized for design of mines and mine exploitation. This program is implemented by mapping the attitude (location, direction, dip, and extent) of induced rock ruptures during the process of hydrafracturing drill holes contiguous to mine interest. The program includes utilization of ancillary naturally occurring stress relief signals, They are precipitated because the earth is indeed dynamic and the strata of the crust are continually adjusting to load and/or strain differentials resulting in rock deformation and fracturing. These fracturing adjustments occur as small to tiny earthquakes comparable to Richter magnitudes of one, zero, minus one, and smaller events termed microearthquakes. Obviously, the earth's stress field changes due to continued differential loading and crustal movements; therefore it becomes conspicuously evident that resolving today's stress field as opposed to paleostresses is most important for efficient, economical, and safe mining operations.

Jan 1, 1974

Eldorado Resources Ltd.(ERL) uses a solvent extraction process for the processing of uranium ores. The solvent extraction plant consists of 4 extraction and 5 stripping stages with regeneration carried out as required (Wyper, 1982). Extraction is carried out with a solvent consisting of 4.5 vol % Alamine 336, 4.5 vol % Isodecanol and 91 vol % kerosene. The extraction step can be represented as In equation (1).

Jan 1, 1988

By M. A. Chandler, G. T. Adel, J. N. Richardson, E. C. Gutierrez

A rapid, bench-top analyzer has been developed to determine P2O5 content and CaO/P2O5 ratio in phosphate ores. The analyzer utilizes a portable computer equipped with a frame grabber to measure the reflective intensity (gray level) of phosphate samples placed in front of a television camera. P2O5 content is related to the average gray level of the sample, while CaO/P2O5 ratio is determined from the amount of bright material present. The sensor is currently being used to analyze flotation concentrate samples at Texasgulf's phosphate operation near Aurora, North Carolina. Sensor development along with results from laboratory and in-plant testing are discussed.

Jan 1, 1993

By W. –E. Marx, M. Faber, R. Pollak, I. Astberg

INTRODUCTION Essentially three strategies are pursued in parallel for protecting the underground working force in mining against the consequences of methane ignitions which might lead to explosions: • Sufficient ventilation for avoiding the formation of explosive methane-air mixtures. • Avoiding sources of ignition caused possibly by electrical equipment or friction. • Structural explosion protection for limiting explosion propagation to the farthest-going extent for the case that methane is fired because of failing of the above preventive measures taken. The corresponding methods taken in mechanized roadheadings with point-attack roadheaders in German coalmining are subject of this paper. VENTILATION In ventilation of roadheading sites the following is to be considered in respect of methane control: • Sufficient air flows by volume being cycled to the heading face for diluting released methane to safe concentrations. • Sufficient local air velocities for effective mixing of methane and air in the whole heading site, in particular directly on the heading face and underneath the roof. Furthermore, ventilation needs to be laid out in a way that cut- ting does not result in health affecting dust exposure at any working place. Accordingly, the ventilation systems shown on Fig. 1 including primary and, if necessary, secondary auxiliary ventilation air ducts as well as dedusters, are used in roadheadings. This equipment is run according to the following principles: • If the roadheader is at standstill, the heading face is ventilated by the free air jet from the blowing duct closest to the face. In this operation phase the deduster is shut-down. • During cutting, the exhaust of the blowing air duct is automatically closed, and the deduster is taken into operation. The in- coming fresh air is now locally discharged via a lateral orifice, or distributed by Coanda-type ducts from the primary or secondary ventilation air duct. In this way, a stable dust wall not disturbed by the jet of the air duct is formed in front of the heading face. Only the ventilation air stream taken in by suction of the close-to-face deduster is passed through the inby zone of the heading face (over approx. 20 m). The clean exhaust of the deduster is dischayed to the roadway in some distance outby. Immediately at the heading face, methane accumulations possibly released by cutting are diluted by compressed-air jets from air-movers located near the roof which assure more rapid motion of the air without distuhing the dust wall. • In the zone of overlapping of primary and secondary duct and the deduster - that zone possibly is poorly ventilated during cutting - sufficient local air speed is assured by Coanda-type ducts or additional ventilation jets for avoiding methane accumulation. The regulations of the inspectorate specifies geometrical conditions to be met with these configurations of ventilation equipment. In-seam roadways are ventilated at rates > 0,5 m/s. For dedusters, present-day ventilation air flows are of 600-800 m+/ min. Ventilation monitoring and control is assured by units for measuring methane and ventilation air flows. If pre-set thresholds are exceeded or fallen short of, these measuring units shut-down - dependent on potential hazard - any not intrinsically safe electrical equipment in the roadheading, either totally or in limited zones. In addition, CO-measuring units near the roadway en- trance serve for early detection of mine fires. In spite of this ventilation layout and the equipment used and in spite of the water spray systems on the cutting head (discussed later in this paper) several cases of methane ignition and subsequent burning off (however, no explosions) have been recorded in the recent past. Therefore, the above-described ventilation is nowadays complemented in many cases by machine-mounted ventilation equipment for the immediate surroundings of the cutting head. Ventilation of the surroundings of the cutting head Investigations carried out subsequent to the above-mentioned gas ignitions have shown that the high ventilation air speed necessary for rapid dilution of methane could not permanently be arrived at in the following zones: • The direct zone of cutting, in particular during sumping. • The floor zone above the debris, predominantly below the cut- ting head. Accordingly, VOEST ALPINE-Bergtechnik, a producer of mining machinery, in cooperation with DMT developed for point- alttack roadheaders a novel machine-mounted ventilation equipment, the Jet-Block" (AERO SAFE Jet-Block) shown on Fig. 2. This system allows to ventilate the above-mentioned critical zones with high flow speeds. One AS Jet-Block is mounted on each side of the boom approx. 0.5 m behind the cutting head. The blocks discharge compressed-air jets with high energy from 10 nozzles per block into the hazardous zones (Fig. 3). Two nozzles of each jet block are tangentially oriented toward the upper circumference of the cutting head, the others are arranged fan-like with orientation to the heading face underneath the cutting head and the debris. The nozzle array of the blocks as well as the com-

Jan 1, 1997