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By J Gutzmer

The Kalahari Manganese Deposit in South Africa accounts for 80 per cent of the worldÆs land-based mineable Mn reserves. Although the ores are primarily mined for export, South Africa is the worldÆs third largest producer of ferromanganese and ferrosilicomanganese alloy, both of which are derived from the smelting of these ores. Mineralogical analysis has traditionally been forsaken for bulk chemical assaying in quality control of smelter feeds, principally because quantitative data could not be easily produced. Yet, mineralogy plays a vital role in determining smelting behaviour, which in turn has economic implications when aspects such as energy and reductant consumption are considered. Smelting is an endothermic process, and the amount of energy input required is dependent on the minerals present in the ore, as well as their relative proportions. Further, knowing the bulk Mn oxidation state in the ores allows for calculation of the amount of oxygen that must be driven off to produce alloy, and hence the amount of reductant required. Additionally, certain minerals can be correlated with potentially deleterious elements, so that ore mineralogy can indicate penalty element distribution. Mineral abundance analysis was conducted on ores from the Kalahari Manganese Deposit using quantitative X-ray powder diffraction. Rietveld refinement using a fundamental parameters approach was applied to micronised ore samples. The mineral percentages obtained were validated using mineral chemical data together with bulk major element data derived from ICP-OES. Bulk oxidation state partitioning was then carried out knowing the Mn valence in the minerals. The results show potential for implementation of the proposed method on a smelting plant, where ore blending could be then implemented to achieve consistent feed compositions to smelters. Selective mining could also be undertaken to obtain desirable ore compositions for domestic or international markets.

Jan 1, 2008

At the treatment plant of the Broken Hill South Limited, Broken Hill, the zinc concentrates, with water, are pumped out to a more or less level area, and stored in dams to dry by drainage and evaporation.In-the construction of these dams a clay bank is first thrown up around the proposed dam site. The concentrate and water mixture are then run in from the perimeter, the solids being continuously shovelled up to increase the bank height, while the clear water is drained off at the centre and returned to the treatment plant.These dams vary in size up to 57,000 sq. ft. in area; when completed the banks are about 12 it. high, and the capacity for the largest dams is about 350,000 cub. ft., say, 20,000 tons.The survey office is called upon for a monthly survey of these dams, generally three of which are in process of building or refilling. The puggy nature of the material prohibits walking beyond the bank of the dam, therefore the following method of estimating concentrates was evolved. No originality is claimed, but as the need is for a true survey, and the results have shown the accuracy of the method, a description is warranted. The dam site is first laid out into 10-ft. squares with a theodoliteand 150-ft. steel tape, the outside lines being placed about 15 ft. from the clay bank - 15 ft. is the maximum convenient distance from the bank for working with the levelling staff mentioned later.As the dam is rarely rectangular in plan, the outside points pegged out are not always the corner of a square, but are placed to give the greatest convenience in later work, that is to say, there may be triangles and irregular figures. The plan (Fig. 1) and photographs (Figs. 5 and 6) will give the general idea of the layout. At each point is driven a 3 ft. 6 in. round iron peg about 3 ft. into the ground. This peg is to permanently mark the point, and is not liable to be...

Jan 1, 1925

By Arland R. Krueger

You have asked me today to tell you how quarried stone is meeting the challenges of contemporary architecture. The new position of stone, the oldest building material, in contemporary architecture, was described to me very concisely the other day by a very distinguished avant garde architect. He said rather wryly, "Do you know, if quarried stone had only just been discovered, we would all be calling it the most miraculous of all the modern miracle building materials." His prognosis was, I believe, much more than a witty quote. It echoes the surprise and. enthusiasm with which a considerable segment of the architectural profession is rediscovering stone as a most modern building material that offers unsurpassed values in beauty and practicality - well deserving of the term "miracle".

Jan 1, 1960

By William W. Adams

A larger measure of safety attended the operation of the stone quarries and related plants in the United States during the calendar year 1935 than in any other year for which annual records are available for the industry. The accident rate, covering fatalities and nonfatal injuries that disabled an employee beyond the remainder of the day on which the accident occurred, was 38.19 per million man-hours of work performed. The nearest approach to this favorable record was in 1932 when the rate was 38.48. The rate for 1934 was 41.82; hence the record for 1935 was 9 percent better than that for 1934. Reports from operating companies showed that 51 men were killed by accidents in 1935 and 4,152 men were injured. (See table 37.) The industry employed 73,005 men and performed 110,033,341 man-hours of labor, an average of 1,507 hours of work per man. Measured in man-days, the total volume of labor was 14,623,303, or an average of 200 days of 7.52 hours per day for each man employed. These figures are not strictly comparable with similar figures for the preceding year, as the, coverage of the industry was more complete for 1935 than for 1934 because special facilities were available to the Bureau of Mines for conducting the 1935 canvass that were not available for the 1934 canvass. Reports covering identical plants that were active both in 1934 and 1935 indicate a reduction of about 7 percent in the number of men employed in 1935. This fact suggests that the apparent increase in the number of workers in 1935 is attributable chiefly, if not entirely, to the more complete coverage of operating plants in 1935. The plants from which this inference is drawn employed 21,799 men in 1934 compared with 20,248 in 1935.

Jan 1, 1937

By William W. Adams

The stone-quarrying industry of the United States, including such related operations as rock crushing, rock dressing, and the manufacture of cement and lime, reported a larger volume of employment in 1934 than in 1933. Reports from the operating companies to the United States Bureau of Mines showed an increase in the number of men employed, number of man-days of employment, and total number of man-hours of labor performed during the year. Moreover, the average worker had a longer period of employment during 1934, the gain amounting to 11 percent over 1933. The increase in employment was accompanied by no increase in accidents for the industry as a whole; in fact, the accident rate for 1934 was a fraction lower than the rate for 1933. In some branches of the industry the frequency of accidents increased, but these increases were more than offset by reductions in rates for other branches. Reports for 1934 were received from 1,403 active plants. The working force averaged 64,331 men for 204 days per man, and the total period of employment for all of the men was 95,258,880 man-hours. Each employee averaged 1,481 hours of work during the year. The total number of hours of labor represented a gain of more than 8 percent, and the average working time per employee showed a gain of 62 hours per man.

Jan 1, 1936

By William W. Adams

The stone-quarrying and related industries of the United States made large gains in employment in 1936 over 1935, according to reports furnished by operating companies to the Bureau of Mines, United States Department of the Interior. Not only were more men employed, but also increases were made in the number of man-days of labor performed and in the number of man-hours worked in 1936. The increase in employment, however, was accompanied by an increase in the number of accidental deaths and injuries among the workers and by a slight increase in the accident-frequency rate per million man-hours worked. The fact that the larger number of accidents resulted in only a slight increase in the accident rate is explained by the large gain made in the number of man-hours worked during 1936. The accident rate in 1936, although higher than in 1935, was the lowest and therefore the best that the industry has experienced in any previous year except 1932 since complete and comparable figures first became available in 1916, a period of 21 years. Operators' reports to the Bureau of Mines showed that the industry as a whole employed an average of 80,022 men in 1936 and that the men worked a total of 18,874,254 man-days or 147,064,448 man-hours. Accidents in and about the plants caused 91 deaths and 5,717 nonfatal lost-time injuries among the workers. The number of injuries and deaths represented an accident-frequency rate of 39.5 per million man-hours worked, compared with a rate of 38.2 in 1935.

Jan 1, 1938

By William W. Adams

Accidents to men employed in the quarrying and related industries of the United States were more numerous, absolutely and relatively, in 1937 than in 1936. Fortunately, the entire increase was in the category of nonfatal injuries, as accidents causing death declined in number and in proportion to the number of man-hours worked. Employment increased. More men were employed, more man-days and man-hours were worked, and the average employee had more hours of work than in 1936. Reports covering all commercial operations showed that 84,094 men were employed an increase of 5.1 percent over 1936. The number of man-hours of work performed by the industry was, 158 millions, an increase of 7.6 percent. Seventy-seven men were killed by accidents, a, reduction of 14 from the year before, and 6,348 men were injured and disabled for more than the remainder of the day on which the accident occurred, 11 percent more than in 1936. The fatality rate of 0.49 per million man-hours of exposure in 1937 compared favorably with the rate of 0.62 for the previous year, whereas the non-fatal-injury rate of 40.10 was 3.2 percent higher than the rate of 38.87 for 1936.

Jan 1, 1940

By William W. Adams

The quarrying and related industries of the United States improved their safety record in 1938 by reducing their accident-frequency rate to a lower acid more favorable position than it has occupied at any time except 1935 since comparable accident statistics became available in 1916. The rates for 1935 and 1938 were identical. The number of men employed in 1938, although smaller than in 1936 and 1937, was larger than in any other year since 1930. Volume of employment, as measured by the number of man-hours worked in the industry as a; whole, likewise was larger than in any year since 1930 except 1936 and 1937. Reports from operating companies to the Bureau of Mines, United States Department of the Interior, showed that 77,497 men were employed in 1938, a decrease of 6,597 compared with 1937. This figure represents the average number of employees for the period during which the quarries and plants were active during the year, which in 1938 averaged 223 workdays per employee compared with 241 in 1937. A total of 17.3 million man-days or 133.8 million man-hours of work was shown for the industry as a whole, which indicated a weighted average of 7.75 hours per man-shift. Reports for 1937 showed a total of 158.3 million man-hours for the entire industry and an average workday of 7.81 hours. Accidents resulted in the death of 82 employees, 5 more than in 1937, and in 5,027 nonfatal injuries involving disability for more than the remainder of the day on which the injuries were received. The number of nonfatal injuries was 1,321 less than in 1937. As the number of deaths and injuries was reduced more, proportionately, than man-hours of employment, the accident-frequency rate per million man-hours of work declined, the rate for 1938 being 38.19 compared with 40.59 for 1937. In other words, accident occurrence to the average employee was 6 percent more favorable in 1938 than in 1937 on the basis of actual number of accidents and actual number of man-hours worked during the 2 years.

Jan 1, 1940

By William W. Adams

Progress made by the quarrying and related industries of the United States during 1939 included increases in the number of men employed and the number of man-hours worked and reductions in the death and injury rates per million man-hours of exposure to risk. Forty-seven States reported quarries in operation; in each of 26 States the industry employed 1,000 or more men. Of these 26 States, 16 reported lower accident rates than in 1938. Among the operations of various types for which separate figures are published in this bulletin, the limestone, lime, and cement groups reported lower accident rates. During 1939, 79,449 men were employed in the quarrying industries. The period of operation of the plants averaged 236 clays per employee, with a total working time that equaled nearly 144 million man-hours. Accidents at the plants resulted in 48 deaths and 5,204 disabling injuries among the workers. Expressed as frequency rates, the accidents represented 0.33 fatality and 36.18 injuries for each million man-hours of work performed during the year. The major cause of fatal accidents inside the quarries was falls or slides of rock or overburden; nine deaths were reported from this cause. Four men were killed by explosives and four by falls of persons. Nonfatal injuries inside the quarries were clue chiefly to handling materials; about one-sixth of the total number at all operations in connection with quarries and related plants were in this class. Flying objects also caused numerous injuries, although only about one-half as many as did handling materials. Next in numerical importance were injuries from falls of persons. Then followed accidents caused by falls or slides of rock or overburden and accidents caused by machinery.

Jan 1, 1941

By William W. Adams

Not since complete records of accidents first became available has the safety record of the quarrying and related industries of the United States been as favorable as it was in 1940. The combined accident-frequency rate was lower and therefore better than in any year since 1916, the first year for which complete and comparable figures are available. Although operating companies began to furnish accident reports to the Bureau of Mines in 1911, the reports for that year and the next few years were obviously incomplete as to number of accidents reported, especially slight injuries involving only 1 or 2 days of disability of the injured employees. By 1916 the reports from operating companies appeared to be reliable as to completeness of coverage of slight injuries. Although the number of men employed in 1940 was by no means a record, it represented a gain over each of the 2 preceding years. Likewise, the number of man-hours worked during 1940 was larger than in 1938 and 1939.

Jan 1, 1942

By William W. Adams

A general increase in employment prevailed in the stone-quarrying industry of the United States during 1941 compared with 1940. Likewise, more accidents occurred to men working in and about the quarries, with the result that the accident-frequency rate for the industry as a whole was higher in 1941 than in the previous year. Reports from operating companies to the Bureau of Mines, covering open and underground quarries, as well as rock-crushing and rock-dressing plants, cement mills, and limekilns at or near the quarries, showed a total of 86,123 men employed and a total of more than 22 million man-days of labor performed during 1941. The total working time of the industry averaged 260 days per man. Measured in man-hours, the volume of work equaled 173 million, an average of 2,011 man-hours per employee.

Jan 1, 1943

By William W. Adams

The quarrying and related industries of the United States made a large gain in employment (man-hours of work) in 1942 with a somewhat smaller number of men employed than in 1941. This was accomplished chiefly by increasing the number of workdays per man and also by increasing the length of the workday. In spite of the greater volume of work performed, the industry had a more favorable accident-frequency rate in 1942 than in the previous year. Accident and employment reports from operating companies showed that the industry employed 84,270 men for an average of 271 days per man in 1942, with a volume of work of almost 181 million man-hours. The average workshift comprised 7.93 hours, and the number of man-shifts worked totaled nearly 23 million. Injuries from accidents in and about the quarries and plants caused disability to 6,461 employees, 112 of whom died as a result of their injuries, including 28 employees whose lives were lost in a single disaster. The accident-frequency rate in the industry was 35.73 per million man-hours worked, comparing favorably with a rate of 40.11 for the previous year. However, the figure for 1942 included a death rate of 0.62 per million man-hours which, because of the disaster referred to, was considerably higher than the fatality rate of 0.44 for 1941. Had the disaster not occurred, the fatality rate for the industry for 1942 would have been 0.46. The major disaster in which 28 lives were lost occurred on March 26 at the Sandts Eddy quarry of the Lehigh Portland Cement Co. near Easton Pa.

Jan 1, 1944

By Oliver Bowles

Lime is of tremendous importance to modern industries. In agriculture it is regarded as essential to the continued fertility of many important regions; in building it is indispensable, and in the many ramifications of the chemical industries it is so necessary and so widely employed that it has been designated "the king of all the bases." Figure 1 shows a general view of a modern lime plant producing more than 500 tons of lime daily. In 1924 the production of lime was reported from nearly every State in the Union and amounted to more than 4,000,000 tons, valued at, nearly $40,000,000. For a production of that magnitude between 8,000,000 and 9,000,000 tons of limestone are required. The many problems involved in winning this great quantity of raw material from the natural rock and preparing it for the kilns have in the past received little attention from any governmental agency. Therefore, in compliance with a request from representatives of the National Lime Association in 1922, the Bureau of Mines began a study of problems in limestone quarrying in an effort to advance more economical methods of operation and the utilization of waste material. Field studies were made at many quarries, and the information thus compiled, besides data already at hand from work in other branches of the stone industries, were disseminated to operators in the form of mimeographed Reports of Investigations, eight of which were issued at intervals during 1922, 1923, and 1924. A questionnaire was appended to each report, and quarry operators were invited to contribute additional information obtained as a result of their actual experience and observation. Operators of lime plants have been cordial in their responses and have supplied the bureau with much valuable information. From the data thus obtained, supplemented by later field studies, the revised reports have been combined to form the major part of this bulletin, which is believed fairly to represent present knowledge on the subject of quarrying limestone for lime manufacture.

Jan 1, 1927

By E. G. Hoover

In the mid-I 970s the rallying cry sent out by the aggregate trade associations to aggregate operators was to come to Washington and help design national legislation mandating reclamation of pits and quarries. This collective effort paid off in that aggregate operators were able to assist in the design of "livable" legislation; however, the coal mining industry took some very hard hits. A principal argument used by the aggregate industry was that relatively small parcels of land are impacted, the operations are located in or near urban areas to serve in the development of that immediate area, and are of many years duration; whereas, coal strip mines disturb many acres, are of short duration, and whose products may have world or nationwide utilization. Historically, developments in reclamation are tied closely to the regulatory systems that have been created to control environmental effects of mining. Since reclamation generally results in a cost incurred after the stone, sand and gravel has been mined and does not add to the inherent value of the mineral, there was little incentive in the past for mine operators to reclaim the land. In 1977, the Surface Mining Control and Reclamation Act (SMCRA) became the law for coal mine operators. The law states that, among other provisions, reclamation must "restore the land affected to a condition capable of supporting the uses which it was capable of supporting prior to any mining, or higher or better uses". It is of interest to note that years before the initiation of legislation leading to SMCRA twenty-eight states already had reclamation regulations that covered virtually all minerals. The scope of performance standards found in the state reclamation regulations included slope stabilization, grading, revegetation, neutralization of toxic materials, visual screening, waste disposal, control of drainage, and other sources of pollution and erosion. Environmental legislation and the consequent regulations came about because the public perceived that private industry did not properly value environmental quality and as a result the government became the policeman.

Jan 1, 1998

By L. C. Johnston, J. N. Gills

This paper reviews the basic reactions of the blast furnace and the open hearth furnace, and then discusses the quarrying and sizing requirements of the limestone feed for each. Particular emphasis is placed on the lime-stone at Irish Cove, now being mined under an agreement between Scotia Limestone Limited and Dosco Steel Limited. The drilling and blasting operations are described, along with loading and haulage, plant flow, water supply, power supply and transportation facilities.

Jan 1, 1967

By P. F. MINISTER

AT Lime Spur, Mont., the East Butte Copper Mining Co. has been quarrying limestone for twenty years. The quarry is beside the Northern Pacific R. R. in the Jefferson River canyon, 4 ½ miles east of Cardwell, at Lime Spur, Montana. HISTORY This quarry was opened early in 1900 by Dan Morrison of Whitehall, the discoverer of the Morrison cave, to supply a demand for smelter flux. Limestone was sold to the Pittsmont smelter of The East Butte Copper Mining Co. and to the Butte Reduction Works. As no particular effort was made at the quarry to select the rock that delivered to the smelters was unduly high in magnesia and impurities. The East Butte com¬pany, therefore. Bought the quarry. in 1909 and confined operations to the high-grade beds in order to supply rock of the desired purity for its own smelter and the Butte Reduction Works until the latter shut down. It also developed a market for some of its rock with the sugar factories. The latter market increased until in later years all rock, larger than 4 in. in size over a bar grizzly, was being shipped to the sugar factories, and the rock smaller than 4 in. was being used as a flux in the blast furnaces at the Pittsmont smelter. In 1924, the East Butte concluded a contract with the Anaconda company for the treatment of its ores, and the Pittsmont -smelter -was shut down: which made the minus 4-in. rock a useless by-product. Since there was not enough revenue in the sugar rock alone and also because of limited waste room it became necessary, if Lime Spur was to continue to operate, to increase- the proportion of plus 4-in. rock and to develop a market for the minus 4-in.

Jan 1, 1930

By Dwight Farnham

Description of Quarry THE shale used at the Renton plant of the Denny-Renton Clay Coal Co., for the manufacture of vitrified paving brick occurs in a hill rising from 200 to 300 ft. above the level of the valley in which the plant is situated. The shale deposit, which is of unknown thickness pitches about 10° to the southeast. The 150-ft. face worked extends approximately east and west, so that the clip, as shown by the photograph, is to the left and into the hill. The shale is overlain with about 50 ft. of gravel, 70 ft. of clay, and 30 ft. of mixed loam and gravel, making altogether from 125 to 150 ft. of overburden. Disposal of Overburden The overburden is removed by sluicing. For this purpose a No. 2 Joshua Hendy giant is used, throwing a 12-in. stream', and having 60 lb. pressure at the nozzle. The water is drawn through an 8-in. pipe from Cedar river, about 1,000 ft. distant, by means of a Worthington four-stage centrifugal pump, direct connected with a 100-h.p. motor placed just south of the factory, and 1,500 ft. from the nozzle This plant handles the material satisfactorily to a height of about 75 ft. above the level of the top of the shale. When the higher levels are worked, an auxiliary plant consisting of a four-stage Byron Jackson centrifugal pump with a 100-h.p., belt-connected motor, is thrown into the system. This plant is situated on top of the shale and can be discerned at the extreme right of the trestle work in Fig. 1.

Jan 9, 1914

By Harry Leslie Bullock

With silica making up more than 27% of the earth's crust, its oxides amounting to more than 59% of the igneous rocks and quartz the most prevalent of the main free oxides, it follows that the mining engineer' is in constant contact with quartz, mainly as a gangue material to be removed as completely and economically as possible and sometimes as a valuable mineral to be purified' for the chemical,, ceramic or glass industries. Water scarcity under desert or semi-arid conditions, dwindling water supplies and difficulties of wet waste disposal in many locations and trouble from freezing in arctic locations make dry benefication more and more desirable. Advances made during the last few years in apparatus and methods and a steadily increasing knowledge of solid state physics are widening the field open to the economical application of electrostatic separation.

Jan 1, 1967

By J. Kou

In this paper the activation behavior of quartz using Ca(OH)2 as an activator in quartz reverse flotation with anionic collector was evaluated and their adsorption behavior was investigated using a variety of techniques. The adsorption of the collector KS-I on the surface of quartz with and without Ca2+ was primarily characterized using Quartz Crystal Microbalance with Dissipation technique (QCM-D), which is a high sensitivity in-situ surface characterization technique. The flotation performance was evaluated using a laboratory mechanical flotation cell at different process parameters such as pH, collector dosage, and Ca(OH)2 dosage. The anionic collector evaluated was a commercial fatty acid KS-I. The QCM-D data showed that the collector adsorbed on quartz more readily with Ca2+ as activator. The mass and structural property of the collector layer adsorbed on quartz surface at 2.16×10-3 mol/L of Ca2+, 0.3 g/L of collector and pH 12.0 have been studied using the technique of QCM-D. The chemisorption of the collector KS-I on the surface of quartz in presence of Ca2+ were also demonstrated by means of zeta potential, QCM-D and FTIR analysis.

Feb 23, 2014

By Raja V. Ramani, Wilson Miola

The potential health effects of quartz-bearing airborne dust in mine and mill atmospheres point to the need for the quantification of quartz content in the source material for determining the source-sink relationships and for choosing applicable control measures. While a standard method exists from a regulatory point of view for the sampling of coal mine atmospheres for determining (i) respirable dust concentrations and (i) the amount of quartz in thesamples, there is no generally accepted standard method for quartz analysis in bulk samples of coal and host rocks. Generally, the bulk sample is reduced to a powder for producing quartz analysis samples. Extensive controls are necessary to ensure representativeness of the analysis samples when these are very minute fractions of the bulk samples. Since the amount of analysis sample is not limited, alternative methods for quartz analysis may also be tried. It is, however, necessary to adopt a procedure which will satisfy several statistical requirements to guarantee representativeness of the quartz analysis samples. In this paper, the important factors in the preparation of quartz analysis samples from the host rocks and bulk samples are discussed. The method developed to prepare the analysis samples is outlined. The results of application of the procedures are presented. The procedure developed for quartz analysis sample preparation is based on sound statistical foundations. The procedure has been validated for reproducibility and homogeneity.

Jan 1, 1991