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By J. Koster

During the past several years, alunite from the Marysvale (Utah) region has been the subject of investigation by the Electrometallurgical Section of the Bureau of Mines. The nature and occurrence of this mineral, with considerable data on the Utah deposits, together with a number of results of preliminary experiments, have been given in a previous report.6/ The geology of the Marysvale region has been reviewed recently.7/ The present paper reports the results obtained by a method involving the sintering of alunite with boric acid and subsequent treatment of the sinter to produce alumina and potassium sulphate.

Jan 1, 1939

By J. Koster

During the past several years, alunite from the Marysvale (Utah) region has been the subject of investigation by the Electrometallurgical Section of the Bureau of Mines. The nature and occurrence of this mineral, with considerable data on the Utah deposits, together with a number of results of preliminary experiments, have been given in a previous report.6/ The geology of the Marysvale region has been reviewed recently.7/ The present paper reports the results obtained by a method involving the sintering of alunite with boric acid and subsequent treatment of the sinter to produce alumina and potassium sulphate.

Jan 1, 1939

By Leiting Yue, Peng Ren, Yu Shen, Zhihong Liu, Haibao Shao, Longgong Xia, Feng Yu

The Kennecott-Outotec Flash Converting technology has been proven as an advanced and mature process in 5 individual plants during the past 2 decades. High grade copper matte (65–72%) produced in the flash smelting, or other smelting technologies is granulated to 3-5mm granules in a water torrent, and further crushed to fine powder (≈50µm) and dried to contain less than 0.3% H2O. Oxygen enriched air, together with fine copper matte powder and lime flux are injected into the reaction shaft by a matte burner. The copper making and slag making reactions will happen in very short time and distance during the particle falling and settling. However, industrial practice has found negative effects caused by sodium contamination. Na is introduced in the copper matte granulating process, and appears as Na2SO4 on particle surface. When Na content was high, scaling problems in the boiler will be worse, and the processing air will be blocked by the growing accretion around the matte burner, and as-produced blister copper is always high in S and O. In this present study, an industrial matte sample was used in the experimental work. Na was introduced into the matte powder by Na2SO4 solution soaking. The burning behaviour of the doped copper matte powder has been investigated as a function of the impurity concentration and processing temperature. Morphology and composition of these samples explained how Na2SO4 converts and reacts in the oxidizing atmosphere, and how they or their converting species influence the burning behaviour of matte particles. Cross-sections of as-prepared samples were analyzed with SEM-EDS, and the reaction mechanism has been carefully interpreted. Results from the present study can benefit both academic and industrial people. INTRODUCTION "Flash Converting" technology was developed jointly by Kennecott Utah Copper Smelter and Outotec (Finland) OY in 1992. The first industrialization of the technology was in Utah Smelter in 1995. Since 2006, it has been successfully applied in Xiangguang Copper, Tongling Jinguan Copper Branch, Fangchengang Jinchuan Copper, and Ningde Southeast Copper. The technology has also been further developed in those smelters. At present, roughly 2 million tons blister copper is produced annually through the Kennecott-Outotec Flash Converting technology, accounting for more than 10% of global primary copper production. The technology has advantages of high efficiency, high sulfur capture rate, good in environmental issues, mature equipment supporting, high automatic control level, low comprehensive energy consumption and flexible connection with the smelting unit, which make the technology to be one of the best choices in investing a new large-scale copper smelter or updating an old copper project in the world.

Jan 1, 2019

By R. H. Zeng

Many subsidence researchers in the U. S. have developed new empirical function methods to predict subsidence, or attempted to validate some empirical functions developed by foreign researchers for use in the U. S. An attempt is made in this paper to develop a new empirical function to predict a surface subsidence basin due to longwall mining. In the U. S., the emphasis of empirical methods for the subsidence prediction over longwall panels has been in large part on determining the profile functions for the major cross-sections of a subsidence basin. In this approach, the surface monuments are usually laid out along the major cross-sections and thus, the subsidence profiles developed are restricted for subsidence prediction along the major cross-sections. However in practice many monuments or surface structures for which subsidence prediction for damage evaluation is required, are not laid out along the major cross-section of the basin. In such cases, it is difficult to get either the empirical profile function for the cross-sections where these structures are located or to predict their subsidence based on the profile function developed for the major cross-sections. Therefore, there exists a strong need to develop a subsidence basin function with a reasonable degree of accuracy, which can be determined or confirmed by the data of scattered monuments on a surface basin. The same subsidence basin function can also be used for prediction of subsidence for any arbitrary points over a longwall panel. In 1982, He (1) proposed the clastic theory, for which he developed the basic differential equations describing the movement and deformation of overburden due to underground mining, and performed the selection of best solution for the equations. He found that the Weibull dietribution is the optimal solution. The Weibull distribution has three parameters that vary to fit the subsidence profile so well that the profile function derived from it provides a high degree of accuracy in subeidence prediction. However the results

Jan 1, 1986

By R. L. Atwood

The structure, properties, and composition of commercial chelating-type copper extractants are examined. Characterization of these extractants was accomplished using organic separation techniques and analytical tools such as NMR and IR. Results indicate that only the trans isomer of the diphenylhydroxyoxime (LIX (R) 64N) is capable of copper chelation. The effect of the structural modification of the extractants on the extraction and stripping reactions are discussed.

Jan 1, 1972

By Jamel Sgaoula

During 1998 COGEMA Resources Inc. announced that operations at the Cluff Lake mine will be suspended indefinitely by the end of year 2000 as a result of deteriorating uranium market conditions. To remain profitable, Cluff Lake mine started an aggressive cost reduction program. A cost reduction team was formed to look for ways to lower production costs. The focus of this team was to screen all areas and to come up with ideas to improve the economy of the mine and ensure the viability of the operations over the remaining three years of operations. Among the areas where significant savings were achieved are: (1) replacement of portion of cement with fly ash in backfill; (2) backfill optimization; and (3) new shotcrete plant installation on site for bulk in-house shotcrete production. This paper details the research work carried out by Cluff Lake mine on these projects and results of its application.

May 1, 2001

Major activities of the Bureau of Mines Explosives Research Center during fiscal year 1965 (July 1, 1964, to June 30, 1965) are reviewed briefly. Part 1 summarizes significant accomplishments of the projects that were active during the report period. Part 2 presents short abstracts of the publications that appeared in the Bureau series and in other media during fiscal year 1965. Publications issued after June 30, 1965 are noted where pertinent in footnotes but are not abstracted.

Jan 1, 1966

By R. W. Raymond

EDWARD COOPER, was born in New York City, October 26, 1824. His father, Peter Cooper, to say nothing of manifold reasons for fame as an inventor and philanthropist, deserves to be remembered as a pioneer in the establishment of public schools; and it is not surprising that he sent his son to one of the democratic institutions in which he was himself so ardently interested. From the public school Edward Cooper went to Columbia. College, where he made the acquaintance of Abram S. Hewitt, who was first his tutor, afterwards his traveling companion, brother-in-law, business partner and life-long friend.* For twenty years I was the consulting engineer of the firm of Cooper & Hewitt, and also connected with the work of the Cooper Union, in which they were both deeply interested and faithfully active. On the basis of the intimate knowledge thus gained, I venture an estimate of Edward Cooper's character and career which, if not fully comprehensive, may facilitate a juster estimate than would be reached by the strident of those data which the modesty of the man permitted to be placed upon public record. Edward Cooper's mind was one of the most active, accurate and subtle with which I have ever come into contact: He had inherited from his father a sunny, benevolent temperament, and' the irresistible impulse to attack all new problems which challenged his attention. His thorough education had 'indeed made him wiser than his father, both in philanthropy and in technical inventions. He could condemn and reject a proposition which Peter Cooper would have embraced, in a splendid, though ignorant, faith that nothing was impossible to an. American, and that the word ? impossible " was simply a label,

Jul 1, 1906

By James S. Browning

For the past several years, the Bureau of Mines has conducted laboratory and continuous process development work on weathered mica pegmatites and micaceous schist ores to determine the feasibility of recovering commercial-grade mica concentrates by flotation. The research has resulted in the development of two processes for flotadon of mica: an acid cationic method for recovery of coarse mica, and an alkaline anionic-cationic method for recovery of fine mica. The research indicated that the two processes may be effectively utilized separately or in combination for flotation of mica from weathered pegmatites and micaceous schists. Concentrates containing over 98 percent mica, with recoveries ranging from 77 to 92 percent, were obtained from the pegmatite ores. The micaceous schist ores yielded concentrates containing 95 to 98 percent mica, with recoveries ranging from 70 to 83 percent. Part 1 of this report summarizes the process development work and demonstrates the feasibility of producing commercial- grade mica concentrates. The report also includes details of commercial beneficiation and grinding of .mica.

Jan 1, 1973

The Maddingley brown coal seam at Bacchus Marsh, where mined and bored, tends on the whole to a higher content of volatile matter than the Latrobe Valley brown coals, and this masks the presence of lignitic or earthy coal bands in the bore core analyses. Visits to the Lucifer Open Cut, at Bacchus Marsh, during 1948, revealed, however, a banded condition in the coal seam, as shown in Fig. 1. This banding showed in a face that had been exposed for a considerable period of time, permitting partial drying out and oxidation of the surface coal. The bands consist of different coal types, ,comparable with those found in the Yallournand Latrobe brown coal seams(l).The' light coloured bands in Fig. 1 consist of a buff to light-brown earthy coal of low specific gravity, that closely resembles the pollen coal, that occurs, as similar thin bands in the Yallourn and Latrobe seams. The 40 ft. of coal above the uppermost of these light coloured bands dries out on exposure to a black, closely cracked surface, composed of small dice-like fragments of a lustrous vitrain-like substance, and in every respect resembles the lignitic coal bands of the Yallourn and Latrobe seams.The coal between and below the light-coloured bands develops fewer and more widely spaced shrinkage cracks on drying out, and remains brown in colour and earthy in appearance, resembling the earthy coal of the Yallourn and Latrobe seams.Representative samples were cut of these coals, taking care to exclude surface coal, and analyses were made of them by the Metropolitan Gas Company, through the kindness of Dr. R. S. Andrews, Chief Chemist to the Company...

Jan 1, 1948

By G. St. J. Perrott

Through the development of manufacturing processes whereby ethylene glycol can be made on a large scale; ethylene glycol dinitrate is now being used in high explosives (dynamites and permissible explosives) by some manufacturers as a low-freezing ingredient of the "explosive oil" instead of such compounds as nitropolyglycerin and nitrosubstitution compounds. The amount of ethylene glycol dinitrate being used constitutes 25 to 50 per cent of the oil. The purpose of this report is to give the results of toots, to determine the effect on the safety and physical properties of permissible explosives of subsituating 25 peg cent of ethylene glycol dinitrate for an equal amount of nitroglycerin or a mixture of nitroglycerin and nitropolglycerin.

Jan 1, 1929

By Robert D. Pehlke

"The evolution of oxygen steelmaking is reviewed and new operating processes are described. The developments which could impact this technology are summarized. Staged and continuous steelmaking are considered in the light of new technologies. The future opportunities for oxygen steelmaking processes are overviewed. IntroductionThe use of oxygen in steelmaking was originally brought on the scene by the development of pneumatic steelmaking. Sir Henry Bessemer in England originally conceptualized the use of gaseous oxygen in steelmaking, and then he and William Kelly in Eddyville, Kentucky independently developed the original pneumatic process which involved blowing air through a bath of molten pig iron to oxidize the carbon and silicon and produce steel. This process and many following processes, including those which would use pure oxygen gas, have been proposed.Beginning with the first commercial oxygen steelmaking vessels at Linz, Austria in 1952, the world steelmaking industry has adopted this style of processing. In general, the process has involved the use of steel scrap in amounts from 20 to 35% of the metallic charge with molten pig iron produced in blast furnaces making up the remainder. The impurities in the charge are oxidized through the use of oxygen gas injected into the steelmaking vessel.However, currently being adopted into commerical practice and on the horizon are a number of advances in this process which include the use of iron ores as a source of iron and oxygen, the use of an all scrap charge, incorporation of pre-reduced iron, the use of auxillary fuels to change the balance of cold and liquid iron-base charge materials and numerous refining techniques."

Jan 1, 1988

By R Osterman

As mining companies have to go deeper in search of ore and coal, the importance of protecting the highwall increases. Wall fatigue also increases with importance of the long life expectancy of a highwall, in particular the impact of fatigue influenced by resonance. Resonance is the tendency of a material to oscillate with greater amplitude at certain frequencies when exposed to a periodic force. Until recently, only dominant frequencies, either natural or induced, were all that could be measured through the fast Fourier transform of the blast-induced wave form.This paper presents a novel method to accurately predict the resonant frequency of a highwall. In fact, the method can predict the natural frequencies between any two monitoring points placed in line with the source of impact, and as such it can be used to determine the resonant frequencies of any physical object. The method not only predicts the resonant frequencies of the material; it predicts the structural response of the total frequency spectrum. This method helps describe the response of a mechanical structure to excitation. It describes the structure’s efficiency in the use of energy, that is, whether energy is dampened or consumed in resonance.The initial predictions have been so accurate that it made it possible to determine the fundamental frequency and the first six harmonics of a highwall in a northern Queensland coalmine. With the use of electronic detonators, the blast can be timed with a repeating delay to create an induced artificial frequency that has been determined to retain the least amount of energy.CITATION:Osterman, R, 2015. Transfer function – new method to accurately predict resonant frequencies of a highwall, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 233–244 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By P B. Swart, P D. Erskine

Despite an increasing focus by media, communities and activists driving an elevated regulatory focus in Australia and indeed some other mining jurisdictions, the mining industry globally has had limited successful mine lease relinquishments and transfers to support a next land use.Critique from anti-mining lobbyists frequently uses the large estimates from historically abandoned mine sites to influence risk-averse regulatory reforms to improve environmental performance. The mine rehabilitation regulatory processes in Australia, and specifically in the State of Queensland, are thus largely in place to prevent mining operators from abandoning their obligations.Regulatory responses to the lack of mine rehabilitation and closure performance in the last five to ten years have primarily focussed on compliance and enforcement of rehabilitation conditions in environmental approvals. Additionally, financial assurance measures have been tightened to protect against abandonment of rehabilitation obligations by the Industry, including the Chain of Responsibility legislation (Queensland Government, 2016b) in April 2016, to hold to account those who have benefitted from mining and processing/refining projects, and then avoid their environmental obligations.CITATION:Swart, P B and Erskine, P D, 2018. Are our closure planning and regulatory processes adequate to identify, quantify and appropriately transfer residual risks after successful mine rehabilitation?, in Proceedings Life-of-Mine 2018, pp 155–158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By Ellis J. Brien, O&apos

This afternoon I would like to talk to you about coal, its defi- nition, its constituents, its associated minerals and present and future coal preparation techniques. This discussion will be an attempt at presenting sufficient coal preparation and associated fundamentals to enable you to understand "deep cleaning", a more advanced beneficiation process which will be commercially practiced in the near future.

Jan 1, 1976

By H. H. Rachford, W. P. Schultz

The use of computing machines to solve physical problems has made it imperative to represent physical data in a form computing machines can use. Although curve-fitting is an old and well-practiced art, there still seems to be some interest in questions regarding what methods can be used and why. Even though there are many good references on this subject, it may be of some value to discuss a particular method which has been found to be useful, and to make available the associated tables for its use in the hope that there can be saved a few of the tedious hours necessary to reduce many of the suggested methods to practice. Although a very brief discussion of the mathematical background of the tables is included immediately below, those interested only in their use can skip directly to the section on Use of the Tables. Direct Fit of a Set of Points A frequently encountered problem is: Given data which can be represented by a smooth curve +(x), to find an easy-to-evaluate function F(x), with only a few coefficients, which is a good approximation of +(x) on the interval 0 5 x 5 x,,. Consider F(x) as a linear combination of m + 1 arbitrary, single-valued, continuous, linearly independent functions, f,(x), Ff.r) = a,f,,(x) + a,f,(x) + . . . -+ aifi(x) + If the value of Q(x) is known or can be read from the curve at the points xj: +(x,), +(x,), . . . +(xj) . . . +(x.), and if n = m, then all the coefficients of F(x) can be determined, and F(x,) — +(x,) = 0 for j =. 0, 1, . . . n. This follows from the solution of the set of linear simultaneous equations. +(x<.) = aofu(x,) + aJI(x0) + . . . + a,,f,,(x,) =a, = f,,(x,) + a,f,(x,) + . . . + a,f,,(x,) +(x,,) = a,,f,(x,,) + a,f,(x,) + ... + a,,f.,(x,,) ...........(2) for the coefficients ai. Although the set a, from the solutions of the set of Equations 2 yields an fix) which gives an exact value of $(x,) for the n + 1 points, there is no restraint on ~(xj in the interval xi < x < xj+,. Indeed, if the points +(x,) are not sufficiently smooth, very serious differences may arise between F(x) in the interval and the smooth curve +(x). Least-Squares Fit It has been suggested&apos; that if n is made to exceed m, and the set a, is found to minimize the function the function F(x) is much less sensitive to small errors in +(xi), and usually provides a much better fit to the smooth function +(x). This is known as the best fit in the sense of the least-squares error. To minimize $, set £ = 0,i = 0,1,... iTi,.....(3) The m + 1 equations from Equation 3 are k—n k=n a.^p /,,(a) f,(xt) + a, X A: = 0 k=O k = n k = n k=0 k=0 +(x.) f,(x,),............(4) one equation being obtained for each i = 0, 1, . . . m. Inasmuch as the arbitrary functions f(x) may be evaluated for x,, k = 0, 1, . . . n, and the +(x,) are known values of the curve to be fitted, the simultaneous Equations 4 may be solved for the set a,. Particular Functions Given the functions fi(x) and the set +(xj), the solutions for require evaluating a number of sums of products as well as the solution of an m + 1 order set

Jan 1, 1956

By M Eggers, H Baxter

This paper discusses the geotechnical condition of bedding shears and small- and large-scale faults and shears in Archean banded iron formation (BIF) bedrock, based on observations of core and televiewer images. Information that can be collected includes the orientation of defects, infill thickness, strength and material type, defect shape and surface roughness.The spacing and continuity of bedding shears may be critical to slope design where performance is structurally controlled with bedding dipping out of a wall. The intensity of development of the bedding shear is a useful indicator of the amount of shearing a bedding surface has been subjected to. This can allow for engineering judgement to be used in adopting peak or residual shear strengths along defect surfaces when developing the design.The spacing and continuity of bedding shears may also contribute to the blockiness and degradation of a rock mass where the structural orientation is otherwise favourable. Additionally the condition, thickness and strength of infill of major fault structures can affect slope design and performance, depending on orientation.Comparison of the condition of structures observed in core with the corresponding in situ televiewer image has been made to assess what characteristics are most accurately captured by each technique and whether the additional information gathered from using the televiewer technique is justified by the cost. The question of whether the data collected by a televiewer is sufficient to ultimately replace the need for core is considered.CITATION:Baxter, H and Eggers, M, 2013. Fault and shear characterisation in archean banded iron formation bedrock - a comparison between core and televiewer data collection techniques, in Proceedings Iron Ore 2013 , pp 47-56 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By Cecil Desch

THIS annual lecture, under the auspices of the Institute of Metals Division, and which was illus- trated by lantern slides, has been printed in full and a limited number are available for distribution on request. Some excerpts from the lecture are given below: Ever since the simple geometrical relations of crystals were discovered, it has been recognized that their proper-ties are best explained by assuming that their ultimate particles are arranged on a space lattice, and that the char-acteristics of that lattice determine the shape of the crystal and its physical and mechanical properties. Modern ex-amination by means of X-rays has widened that concep-tion and given it greater; definiteness, and the atoms are now regarded as the particles forming the space lattice. The splendid achievements of investigators in this field have made it possible to state, for a large number of sub-stances, the form and dimensions of the lattice. The char-acteristic of a lattice is that a unit of simple geometrical form is repeated at regular intervals in three dimensions so as to fill the entire crystal. It follows that there must be certain planes in which the atoms are more closely packed than in planes drawn at any angle to them, and it is these planes of closest packing which play the greatest part in determining the growth and other properties of the crystal. There are actually two stages in crystallization, what-ever be the medium in which it occurs. The first is the ap-pearance of crystal nuclei; the second the growth of those nuclei to form crystals of appreciable .size. The first is clearly a kinetic phenomenon. In the molten mass, solu-tion, or vapor, the molecules are in a state of rapid motion and frequent collision. When the temperature has fallen so far. that it is possible for a crystal to exist, a few col-liding molecules may fail to rebound, and so become at-tached to one another, the balance between the attracting and repelling forces-between them causing them to arrange themselves on a space lattice, to which other molecules sub-sequently attach themselves. It was once maintained that the X-ray evidence demanded that the molecule should dis-appear in the solid crystal, but this was a wrong inference, and in many crystals, but not in all, the chemical molecule retains its identity in the solid state. In pure metals the atom and the molecule are identical, so that the conditions are unusually simple. How many. nuclei will be formed in a given mass is evi-dently a problem in probability. Experiments to deter-mine the relation between the temperature and the number of nuclei formed in a given time have been made with some success by using viscous organic substances, but metals offer much greater difficulties, and the few determinations which have been published are vitiated by serious errors. However, the examination of sections of ingots of the same composition and cast at &apos;the same temperature in similar molds will show, that the number of crystals does not vary widely.

Jan 3, 1927

By S. Banisi, M. Poorkani, M. Farzaneh, M. Askari

"At the Sarcheshmeh copper mine 40,000 t of ore per day with an average grade of 0.9 % Cu is ground to 70% passing 75 microns. Grinding is effected in 8 parallel lines of 8 x 5 m ball mills in a closed circuit with cyclones. The make-up balls are 80-mm forged alloy steel balls and the average ball consumption is 750 gh of ore ground. In order to optimize ball size distribution inside the mill, based on the previous investigation instead of using only 80 mm make-up balls a combination of 80 and 60 mm (75% to 25% by weight) ball charge was used in one of the mills. To evaluate the performance of three ball types namely forged alloy steel balls (A), ductile cast iron (C), high chromium cast iron (D) and also a combined (80 and 60 mm) charge of forged alloy steel balls (B), four identical parallel mills were charged accordingly. These four mills were sampled during a period of six months. The amount of material finer than 75 microns of cyclone overflows was selected as a criterion for the performance evaluation. It was observed that in a mill with the combined make-up balls the amount of fine produced was 4% higher than the other mills. The consumption of ball types A, C and D were 730, 710 and 534 g/t, respectively. The results of laboratory flotation tests showed that due to an improvement in the production of fines an increase of 1.4% in the overall copper recovery is obtainable. Due to the promising results, the new make-up ball regime was implemented in all mills in the plant.INTRODUCTIONThe Sarcheshmeh copper ore body which may rank as third or fourth largest in the world contains 1 billion tonnes averaging 0.90 % copper and 0.03 % molybdenum. It is located southeast of Iran and has been processing 40,000 t/d of ore since 1982. The mine produces 100,000 tonnes of copper and 2,200 tonnes of molybednite concentrate per year. After three stages of crushing, the ore with a F80 of 12.7 mm is fed to 8 parallel ball mills in closed circuit with cyclones to produce a product 70% finer than 75 microns. The concentrate of the first stage of flotation is reground and the tailing constitutes the main component of the plant final tailings. A concentrate with an average grade of 31% Cu is obtained after cleaning and re-cleaning stages. Total recovery of the plant varies between 83 and 87 % depending on the operating conditions and ore type."

Jan 1, 2002

By Wenying Liu, Marek Pawlik

Long-chain ionic surfactants, with fatty acids and amines as the most important representatives, are widely used as collectors in froth flotation. These surfactants, generally referred to as weak electrolyte collectors, frequently form solid insoluble precipitates within a certain pH range. However, the action and behavior of these colloidal precipitates in froth flotation systems are not well understood and has not been well decoupled from those of dissolved forms. The objective of this study was to understand and compare the role of colloidal precipitates with that of the dissolved forms at gas-liquid and gas-liquid-solid interfaces. Using primary amine as the model surfactant, experiments were carried out to measure: the maximum volume of bubbles generated in the presence of dissolved and precipitated forms of the surfactant; surface tension for both forms of the surfactant using the drop shape and maximum bubble pressure methods; and contact angle using the sessile drop method. The experimental results showed that: in the presence of the precipitate, bubble volume was smaller, which was correlated with the lower surface tension and higher contact angle measured; the surface tension of solutions containing surfactant precipitate was affected by the surface age of liquid droplets. This study enhances understanding of the interfacial behavior of long-chain ionic surfactants under different conditions, which would help improve the efficiency of reagent utilization in froth flotation.

Jan 1, 2014