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By K. C. Strebig, C. W. Schultz, A. A. Selim

The effect of some organic additives in diamond drilling of quartzite was investigated in the laboratory. The drill was designed to measure the rate of penetration, the thrust, and the torque and to record each as a function of the distance drilled. A statistical plan was followed throughout the investigation and an equation representing the bit performance was derived from the mathematical theory of reliability. The drilling torque was found to increase with the use of additives while the sliding coefficient of friction and the wear coefficient decreased. The energy per unit volume consumed was found to increase with the use of additives. A hypothesis explaining the effects achieved with the additives is given. INTRODUCTION For some time researchers have attempted to increase drilling efficiency by adding certain agents to the flushing medium. Much of this interest is the result of the observations of Rehbinder, Shreiner and Zhigach1 They postulated that "...in processes for the mechanical destruction of solids, a region of increased crack formation is created in the deformed layers adjoining that surface of destruction, forming the predestmction zone. The surrounding medium (for example, a liquid) which wets a given solid will penetrate the embryo microcracks of the predestruc-tion zone. Increasing the molecular affinity of this liquid for the surface of the solid considerably facilitates the deformation and destruction by softening the solid in the zone of increased crack formation. In this manner, the hardness or strength of the deformed body is decreased by the influence of the penetration of the liquid into the predestraction zone." This is known as the "Rehbinder effect". Rehbinder's work has prompted many investigators to examine the effect of additives on the mechanical destruction of rocks. Engelmann, Terichow and Selim reported that the maximum penetration of the rock by a diamond point in a solution environment was at the isoelectric point of the solution.* Robinson reported that his results did not appear to support the theory of Rehbinder.3 Joris and .McLaren suggested that additives with surface tension lower than water will be more efficient in cooling the diamonds.4 Their effectiveness in removing the fine cuttings from the face of the bit will also improve the efficiency of the system. They reported an improvement in impregnated bit life and penetration rates with the use of soluble oil additives. In contrast, Long and Agnew, drilling with surface set bits, reported that lubricating agents increase bit temperature and wear.5 A significant change was reported6 in the mechanical properties of rock with polar additives. It was concluded that this change in the mechanical properties of the rock in the presence of the additive is due to the rock hydrophilic properties. Ethylene glycol, glycerine and anionic detergent were selected for this investigation because their surface tension is lower than that of water. The surface tension of these additives for the concentrations studied was 42 to 75 percent of the surface tension of water. A low surface tension additive would wet the surface of the diamonds more easily and hence would be more effective in cooling the diamonds. Another characteristic of these low surface tension additives is their effectiveness in removing the cuttings and preventing the flocculation of the formed particles in the drilling process. This article summarizes the results of an investigation performed at the laboratories of USBM, Twin Cities Mining Research Center. The objective of the investigation was to study the over-all effects of some organic additives on the performance of diamond impregnated bits in atmospheric drilling conditions only and not in downhole pressured conditions.

Jan 1, 1970

By J. B. Cheatham, M. D. Biggs

This paper presents a systematic method for determining the forces on a simplified roller bit. The kinematics of an actual roller bit drilling in rock is complex; nevertheless, it is desirable to obtain an accurate analytical model.. As a preliminary study, the roller bit is represented here by a simple two-dimensional bit and the rock by a Coulomb plastic material. Results from previous work, plus additional assumptions, are incorporated into a computer program to determine the forces required to move the bit in a specified manner. Example problems are worked by use of this program. By studying similar drilling problems and by supporting laboratory work, one could eventually obtain an accurate analytical model for drilling by an actual roller bit. This could lead to the compilation of a catalog of results that, in turn, would allow selection of the optimum drill bit for any given situation. INTRODUCTION

Jan 1, 1970

By McIntosh A. H, Torlach J. A

Since the last paper on mining methods was presented to the Annual Conference of the Australasian Institute of Mining and Metallurgy in 1:960, numerous advances have been made in drilling and blasting techniques at Mount Morgan. This paper describes the drilling and blasting methods being employed in the open cut. The change over to track mounted percussion drills for all types of primary drilling is almost complete and new techniques such as detergent drilling and pressure loading of ANFO are being applied successfully.

Jan 1, 1965

By T L. Horsley

This paper deals with the drilling and blasting methods employed at the Cassiar mine, which is located just south of the B.C.-Yukon border. It covers both the "pit" and "peak" mining operations. Specific problems, such as working in frozen ground, are discussed, and the breaking characteristics of the various rock formations are outlined. The paper concludes with a brief mention of the equipment used in the operation, as "~ell as an outline of the breaking costs. Introduction T HE Cassiar asbestos mine is located just south of the British Columbia -Yukon border high on a spur of McDame mountain. Chrysotile asbestos fibre occurs in a faulted enlargement of a serpentine sill lying conformably be-tween a series of sedimentary beds and volcanic flows which dip at 45 degrees into the mountain. One end of the orebody is eroded by a cirque in which a layer of permanently frozen ore and waste talus lies at the end of the mining benches. The topography at the mine is steep, with no flat areas. Roads, dumps, and areas for crushing,

Jan 1, 1965

By J S. Kermeen

This paper deals with drilling and blasting techniques at the Phoenix mine, near Grand F1nks, B.C., which is now operated by The Granby Mining Company Ltd. The difficulties of open-pit mining through former underground workings are unique to this operation. Rock types are related to drilling conditions, and the methods used, or contemplated, to overcome the several difficulties are outlined. The equipment used is also mentioned. Finally, blasting techniques and costs are reviewed. Introduction T HE Granby Mining Company operates on open-pit copper mine and concentrator at the site of the original Phoenix mine, near Grand Forks in south-central British Columbia. The pit is a side-hill cut measuring approximately 1,000 by 2,000 ft., and covering a vertical range of from 4,550 to 4,950 feet above sea level. The mill is currently operating at 1,900 tons per day. A 4.5 to 1.0 waste to ore ratio necessitates the removal of some 15,000 tons of ore and waste per working day. Mining conditions at Phoenix are extraordinary in that all the ore zones currently being

Jan 1, 1965

By D. C. Foote

MR. FOOTE: This paper deals with blasting and mechanical loading. The Union Pacific Coal Company does all of its blasting with permissible powder and electric shooting, but this paper deals principally with blasting in connection with mechanical loading. With the introduction of mechanical loading into the coal fields of southern Wyoming one of the main problems to be taken into consideration was the drilling and blasting of the coal. The methods used in blasting coal for hand loading were found to be ill adapted to the mechanical practice, so numerous tests were conducted from time to time to determine a system or systems whereby the coal might be blasted in a form to be easily handled by the loading units. The general practice in blasting coal for hand loading, for example in a room 24 feet wide and seven feet high with an undercut of seven feet, would be to shoot one or two strong breaking shots in the center and one on each rib. While much of the cut would be blasted down in good lump, some coal would be left hanging at the back and ribs. With hand loading, the miners would have time to pull this coal down with a pick between cars and eventually would clean up the place ready for the cutting machine. The loading machine, however, cannot get this coal down and its operation would be delayed while the men were doing the necessary pick work.

Jan 1, 1929

Drilling and blasting are an essential part of most mining operations, and are commonly major operating cost centres. The effectiveness of blasting can have a significant influence on all subsequent activities, and hence overall operating costs. Drilling and blasting systems must be compatible with the overall mining method, to minimise total costs and ensure operational efficiency. Selection of suitable equipment and techniques requires an understanding of the total operation, plus current skills in specialised technologies. This paper examines the contribution of drilling and blasting to total costs, including the balance between capital and operating costs. The use of computer modelling is discussed, to demonstrate how blast performance and costs can be predicted and alternatives analysed. Case studies illustrate how cost savings can be made in operating mines, and alternative systems evaluated to optimise new projects.

Jan 1, 1990

By A Robertson

Australia has been slow in adopting the use of underground space as a part of our urban planning process. Australia has one of the highest levels of tunnel advance per capita per annum in the world, yet the use of underground space in our cities appears difficult for our planners and politicians to comprehend, not withstanding the general availability of good quality rock and contractor expertise in Australia. However, the lack of space in our urban areas is being highlighted as our major cities expand outwards and people and businesses gravitate towards city centres. Typical potential underground space uses include car parking, self-storage and archiving facilities, water storage, underground quarrying, small industrial facilities and another layer of traffic (electric and fuel cell) and services network. Historically, blasting in high density population areas has resulted in blast vibrations and blast overpressures exceeding the limits, which in some case have been set extremely low in terms of peak particle velocity (PPV). This makes conventional blasting difficult, often requiring low charge weights per delay and associated small blast sizes and slow advance rates. However, the introduction of new technologies, such as computer aided drilling, electronic delays and low-energy explosives has made this task considerably easier. Although more expensive than conventional blasting, excavation by blasting using these products and technologies in relatively good quality ground is believed, in most cases, to be less than the cost of mechanical excavation. In this paper, the authors look at innovative trends in underground quarrying, underground commercial space and tunnelling and put forward their concept of future excavation demand, future product requirements and technical specifications to the drill and blast community.

Jan 1, 2007

In order to fully understand why Amax Coal puts such extreme emphasis on the drilling and blasting programs at each of our mines, we must review the past. This paper will discuss the drilling and blasting techniques we used in the 1970s and their evolution to current practices. As time progressed, major changes influenced the surface mining of coal through new more restrictive governmental controls and local communities organising into groups with two goals in mind, one to shut down the mines and the second to try and get rich by making false and unjust damage suits against the mines. In virtually all of our midwest surface operations we have at one time or presently are facing litigation that has reached into the millions of dollars. Amax Coal has worked in co-operation with the United States Bureau of Mines in the areas of blast vibration, shot design, highwall safety, blast casting studies and many more. Today we are continuing to work with Dr David Siskind and his expert staff seeking answers to old and new problems addressing the blasting of overburden and parting seams.

Jan 1, 1995

By D. Scott Scovira, Remi Proulx

The Meikle Mine is a high grade, underground gold mine utilizing primary-secondary longhole open stoping with delayed backfill to produce 3000 stpd of ore. Hot and reactive ground conditions were encountered early on in the mine life. Ground temperatures up to 330” F were measured. In the early stages of mining, the mine experienced premature detonations using different explosives. The learning curve to safely mine this high-grade gold deposit in hot and severely reactive ground was indeed very steep. Currently, the Meikle Mine uses a special buffered bulk emulsion in all blasts to address hot and reactive ground concerns. In addition, exacting procedures are also followed to ensure safe work with explosives. The combination of new explosives technology and strict loading procedures permits high mine productivity with the highest degree of safety.

Jan 1, 2000

By R. P. Proulx

The Meikle Mine is a high grade, underground goldmine utilizing primary-secondary longhole open stoping with delayed backfill to produce 2700 tpd(3000 stpd) of ore. Hot and reactive ground conditions were encountered early on in the mine life. Ground temperatures up to 166°C (330°F) were measured. In the early stages of mining, the mine experienced premature detonations using different explosive products. The learning curve to safely mine this high-grade gold deposit in hot and severely reactive ground was indeed very steep. Currently, the Meikle Mine uses a special buffered bulk emulsion in all blasts to address hot and reactive ground concerns. In addition, exacting procedures are also followed to ensure safe work with explosives. The combination of new explosives technology and strict loading procedures permits high mine productivity with the highest degree of safety.

Jan 1, 2000

By E. D. Gardner

Open-cut mining of copper ores in the western United States is a relatively new industry. At first the mining methods were mainly adapted from those used at open-cut iron mines and at quarries, but now efficient practices that are more suitable for the copper deposits have been developed. The pioneer in this field is the Utah Copper Co., of Bingham, Utah, which deserves great credit for working out much of the early procedure. Stripping began at that mine in 1906, and the large Garfield concentrator was put in commission in 1908. Next in order of development were the Nevada Consolidated Copper Co., at Ely, Nev. ; the Chino mine of the Ray Consolidated Copper Co., at Santa Rita, N. Mex. ; the New Cornelia Copper Co., at Ajo, Ariz. ; the Sacramento Hill mine of the Copper Queen Branch, Phelps Dodge Corporation, at Bisbee, Ariz.; and the open cut of the United Verde Copper Co., at Jerome, Ariz. The Sacramento Hill mine began to produce in 1923, and the United Verde open-cut mine has produced ore mainly in connection with stripping. The writer visited the Utah Copper mine in September, 1923; the Nevada Consolidated in August, 1923; the Chino in July, 1924; and the New Cornelia, the Sacramento Hill, and the United Verde open cut at various times during 1922, 1923, 1924, and 1925, mostly in connection with other work.

Jan 1, 1927

By Rob Farnfield, Ben Williams

The A5 road in the United Kingdom forms an ancient and well-used route through the hills and mountains of North Wales. In the 1990?s a programme of work was conducted to upgrade the road to modern standards. As part of this work a new cutting was constructed to bypass a portion of road routed through a gorge close to the village of Ty Nant. This new cutting was formed by drilling and blasting and included much pre-splitting and extensive rock bolting. This operation caused much concern to local residents relating to vibration, air overpressure and flyrock.

Jan 1, 2011

The Kennedy Siltstone Open Cut provides graded rock for stope filling. Rotary drilling of 310 mm blastholes with a Gardner Denver GD120 is used, and the successful application of an equilateral triangular drilling pattern is described. Charging practices and the development of bulk slurry handling are outlined. Blast monitoring plays an important role in K.S.O.C. drilling and blasting operations. The proximity of nearby residential areas (1300 m) and the Mount Isa Airport (4500 m) necessitates special attention with regard to the minimisation of both air blast and ground vibration levels. The application and control of drilling and blasting parameters has had a direct bear- ing on success of the mining operations and also played an important role in reducing the disturbance to the community.

Jan 1, 1978

By Jorge Flores, Benjamin Cebrian

Blast Optimization at a high altitude mine operation involves not only the selection of the right drilling designs and explosives but also the circumstances of operators working at low oxygen levels and low temperatures.

Jan 1, 2015

By Nelson Severinghaus

THE Rock Chapel plant of Consolidated Quarries Corporation (Fig, 1) is three miles northeast of Lithonia, DeKalb County, Georgia, It was opened about eight years ago for crushed stone aggregate. This paper reviews a number of experiments that have been tried in drilling and blasting, and gives the practice in use today. It also presents several theories on the action of explosives in this type of blasting. FIG, 1.-PLANT OF CONSOLIDATED QUARRIES CORPORATION, WITH QUARRY AT UPPER LEFT. The rock worked is a bare dome of granite gneiss about 3000 ft. in diameter, rising 150 ft. above the surrounding ground (Fig. 2). It is uniform in composition and quality, without seams, and extends down-ward to unknown depth below the quarry floor. A water well drilled 600 ft. remained in the same rock. The principal difficulty encountered in blasting is an easy split, which tends to break down the rock in large blocks.

Jan 1, 1938

By Nelson Severinghaus

THIS Rock Chapel plant of Consolidated Quarries Corporation (Fig. 1) is three miles northeast of Lithonia, DeKalb County, Georgia. It was opened about eight years ago for crushed stone aggregate. This paper reviews a number of experiments that have been tried in drilling and blasting, and gives the practice in use today. It also present, several theories on the action of explosives in this type of blasting. [ ] The rock worked is a bare dome of granite gneiss about 3000 ft. in diameter, rising 150 ft. above the surrounding ground (Fig. 2). It is uniform in composition and quality, without seams, and extends downward to unknown depth below the quarry floor. A water well drilled 600 ft. remained in the same rock. The principal difficulty encountered in blasting is an easy split, which tends to break clown the rock in large blocks.

Jan 1, 1938

By C. A. Pierce

UNDERGROUND operations of the United States Potash Co. at its mine near Carlsbad, N.M., have been continuous since the property was opened about five years ago. Approximately one million tons of potash has been mined and two shafts have been sunk, each to a depth of about 1000 ft. Outstanding in the company's operations is the fact that not a single blasting accident has occurred during the aforesaid period. The purpose of this paper is to describe the blasting practice that has made possible the achievement of this accident-prevention record. The mining method employed in extracting the thick horizontal bed of potash may be described as a double-entry room-and-pillar system. Mine development is kept well in advance of extraction operations, and a three years' supply of ore, at least, is always available. Limits of the orebody have not been determined, and in the present system of mining headings are advanced by a "shortwall" method. This was the first potash ore bed developed in the United States. The nature of the deposit, therefore, was unknown, and it was deemed expedient to outline a conservative mining policy. Later, when more is known about the deposit and certain control ascertained, a "longwall" panel retreating method may be found advisable. The necessity for a domestic supply of potash became a national issue previous to and during the World War. The United States Govern-ment came to realize that this country should not be dependent upon foreign sources of potash, and began extensive explorations in many parts of the country, seeking an orebody that would meet the exacting require-ments of the domestic market. The Department of Interior, through the Geological Survey and Bureau of Mines, made every effort to determine the location of potash deposits and encouraged their exploitation by private capital. Through the combined efforts of the Department of Interior and private industry, the deposit now being worked by the United States Potash Co. was discovered and brought into production.

Jan 1, 1936

By C. A. Pierce

UNDERGROUND operations of the United States Potash Co. at its mine near Carlsbad, N.M., have been continuous since the property was opened about five years ago. Approximately one million tons of potash has been mined and two shafts have been sunk, each to a depth of about 1000 ft. Outstanding in the company's operations is the fact that not a single blasting accident has occurred during the aforesaid period. The purpose of this paper is to describe the blasting practice that has made possible the achievement of this accident-prevention record. The mining method employed in extracting the thick horizontal bed of potash may be described as a double-entry room-and-pillar system. Mine development is kept well in advance of extraction operations, and a three years' supply of ore, at least, is always available. Limits of the orebody have not been determined, and in the present system of mining headings are advanced by a "shortwall" method. This was the first potash ore bed developed in the United States. The nature of the deposit, therefore, was unknown, and it was deemed expedient to outline a conservative mining policy. Later, when more is known about the deposit and certain control ascertained, a "longwall" panel retreating method may be found advisable. The necessity for a domestic supply of potash became a national issue previous to and during the World War. The United States Govern-ment came to realize that this country should not be dependent upon foreign sources of potash, and began extensive explorations in many parts of the country, seeking an orebody that would meet the exacting require-ments of the domestic market. The Department of Interior, through the Geological Survey and Bureau of Mines, made every effort to determine the location of potash deposits and encouraged their exploitation by private capital. Through the combined efforts of the Department of Interior and private industry, the deposit now being worked by the United States Potash Co. was discovered and brought into production.

Jan 1, 1936

By L. van Hijfte, A. Piché

"Drilling and blasting are fundamental operations in the mining cycle and constitute an important component of the mining costs. Problems associated with improper drilling and blasting practices can create losses of several millions of dollars per year. For this reason, a Blasting Technology program was initiated in 1984 at the Noranda Technology Centre (NTC). In this paper, advances made at NTC in drill and blast technology are reviewed. Impacts of drilling and basting for Noranda are assessed in terms of dilution and ore losses. Future challenges are addressed. IntroductionUp to 1997, Noranda was a diversified natural resources company that operated in three sectors: mining and metallurgy, forest products, and oil and gas. The company employs more than 33 000 people in operations and sales offices around the world. Today, Noranda has returned to its roots in mining and metallurgy. The new vision of Noranda is to be dedicated to the responsible and profitable development of mineral resources around the world for the benefit of its shareholders. In so doing, Noranda will continue to be deeply committed to the environment, health, workplace safety, cost competitiveness and return on capital. Technology is an integral part of Noranda’s success strategies. For this reason, the Noranda Technology Centre, formerly known as Noranda Research Centre, was founded in 1963. Since then, it has undergone four expansion phases to keep up with the increasing needs of the businesses. Today, NTC employs more than 220 specialists who work in partnership with different Noranda companies to identify, develop, and transfer technology to the operations, as well as to explore new sectors of activity."

Jan 1, 2000