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By N. N. Moebs

The Bureau of Mines air-sealed a 77-acre) above-drainage coal mine to evaluate sealing as a means of reducing the acid and metallic salt contents in drainage from abandoned mines. An approximate reduction in acidity of 150 ppm (equivalent to 193 pounds per day) and in iron of 98 ppm were directly attributed to sealing. The topographical, hydrological, and other factors involved in air-sealing are discussed, and the construction used to seal the mine is described.

Jan 1, 1970

By Adrian C. Dorenfeld

Laboratory data form the basis for the design of flotation circuits. These data, obtained from testing samples of the ore, should show the optimum con- ditions for concentrating the ore and the effects of change in process vari- ables. Among the more important variables commonly met in flotation practice are: Liberation Size-This is the particle size at which substantially all of the valuable minerals are detached from the gangue minerals. Reagent Additions- Experimental data will show the reagents used and their quantity, quality, and point of addition. Pulp Density-This is an important variable in the design of the flotation circuit because it is one of the factors determining the size and number of flotation cells. Flotation Time-The time necessary to make the separation into concentrate and tailing depends on such factors as particle size and reagents used and must be known for determination of the size and number of flotation cells in the plant. Temperature of Pulp-Temperature affects flotation reactions. Water at approximately room temperature is satisfactory for most flotation separations, but some minerals such as fluorspar are best floated in hot water. Type of Circuit-Many types of circuits can be designed, as discussed in detail later. The laboratory tests should provide data for design of the plant circuit best suited to the ore. Water-Knowledge of the quality of the future plant's raw water is important because water quality may drastically affect flotation results. If possible, flotation tests should be made using samples of the water to be used in the plant. Flotation results may vary with seasonal temperatures and with circulation of reclaimed water. Experimentation can show whether it will be necessary to provide for heating, cooling, treating, or reclaiming the water. Uniformity of Ore-The extent of variation of the ore in hardness, grind- ability, mineral content, and floatability should be investigated so that the designer can ascertain methods to overcome problems caused by ore variations. Settling and Filtration Data-To design the plant flotation circuits, settling and filtration rates and ultimate percentage solids of the various products must be determined. Corrosion and Erosion-Corrosion and erosion tests should be made on the flotation pulps, particularly if the pulps are acid or at an elevated temperature, so that suitable materials of construction can then be chosen.

Jan 1, 1962

By A. R. Videla, P. R. Brito-Parada, I. Mackay

"Linking results from laboratory scale experiments to industrial flotation behaviour is challenging. Typically, such experiments involve batch tests in which the system does not operate at steady-state, making it difficult to infer the effects that operating conditions have on flotation performance. In order to overcome this limitation a 4-litre recirculating tank was previously developed at Imperial College London. This tank is capable of reaching, and operating at, steady-state by recycling overflowing concentrate back into the feed. As well as instruments to control operating conditions, it is fitted with a system of sensors that allow the surface of the froth to be dynamically monitored. From this information, it is possible to measure the air recovery—a proxy for froth stability. Thus, this bench-scale tank can be used to understand the effect of differing operating conditions on flotation performance at steady state. However, so far, this cell has only been used to investigate idealised systems with only one or two species.Reprocessing of tailings dams is not only environmentally desirable but also increasingly economically feasible due to the declining head grades of primary deposits. There is also the added benefit of no further milling being required prior to flotation. However, the effects of fine and ultrafine particles on froth stability are not yet fully understood. In this work, the bench-scale continuous tank has been used for the first time to determine the flotation response of a complex feed, consisting of samples from a copper tailings dam, to changes in operating conditions. It was shown that the froth stability in the system is comparable to that of previous work and industrial tests, with a peak in air recovery being found at a superficial gas velocity of 1.13 cm/s. There is scope to optimize the froth stability of tailings flotation for enhanced metallurgical performance."

Jan 1, 2018

By S. E. Haszko

Fused alumina or silica crucibles were used as the containing vessel. X-ray powder photographs were taken with CrKa radiation and the use of Straumanis type Norelco cameras of 114.6 mm diam. Crystallographic data for these compounds are shown in Table I. These results are in agreement with others of this series reported previousiy by Wernick and Geller.l The abnormally large atomic volume of Eu and Yb metal3 is manifested in EuA12 and YbAl2, when one compares them with the compounds reported in Ref. 1. However, the behavior of Yb in the Ni compound is the same as that observed in Ni5Yb having the Cu5Ca structure.4 Thus, it appears that Yb has a valence closer to 3 only in the Ni compounds; i.e.. the 2s and Id electrons are lost to the conduction band. 1,4 Europium in EuAl2, appears to have a valence closer to 2. In previous work.' X-ray patterns of ingots of NdCo2 indicated a multiphase material with faint indication of the presence of a phase having the MgCu2 structure. It was thought that NdCo2 formed peri-tectically from the melt, resulting in a multiphase system when cooled under nonequilibrium conditions. An X-ray pattern of a sample from a melt cooled more slowly than in past work showed that the major phase was NdCo2. The lattice constant, Table 1, is in excellent agreement with the value one can predict from the data of Ref 1. One of the other phases was identified as Co,Nd. The author wishes to thank J. H. Wernick for his guidance in this work, and D. Dorsi for the preparation of these compounds. 'J. H. Wernick and S. Geller: AIME Trans., in press. 'J. H. Wernick and S. E. Haszko: to be published. 'F. H. Spedding and A. II. Daane: Progress in Nuclear Energy, Series 5, Eds.: H. M. Finniston and J. P. Howe, McGraw-Hill Book Co., 1956. 'S. E. Haszko: to be published. 'J. H. Wernick and S. Geller: unpublished work. 6J. 11. Wernick and S. Geller: Acla Cryst., 1959, vol. 12, p. '162. The Influence of Hydrogen on the Lattice Parameters of Ti-Sn Alloys A. Coucoulas and H. Margolin A reinvestigation of the lattice parameters of Ti-Sn alloys by the present authors has revealed consistently higher c and a values than those obtained by Worrier. The difference is most pronounced in the c-parameters which are, therefore, used as a basis of comparison. This discrepancy was not due to air contamination, since precautions were taken to exclude this possibility. Specimens for Debye-Scherrer photograms were prepared by arc-melting 15-g buttons of Bureau of Mines titanium and 99.99 pct Sn, with compositions of 6, 8, 10, and 12 at. pct Sn. These buttons were forged under an oxygen-acetylene torch to 1/8-in. sq rods to produce relatively fine grained material. Scale and some surface were ground off, and the rods, after wrapping in molybdenum and titanium sheet, were vacuum annealed 15 min at 800 °C to remove hydrogen. Heat treatment of one of the samples at 875°C to produce ß and reveal a at the surface showed no surface contamination. Following the vacuum treatment, the specimens were wrapped in molybdenum and annealed for 1week at 800°C under two atmospheres of argon. After water-quenching, the rods were ground so that the thickness tapered to 0.1 mm at the tips. The ground specimens were then recapsuled as previously and reannealed 1 hr at 800°C to remove cold work. The

Jan 1, 1961

By John S. Owens

The National Steel Pellet Project and the Butler Taconite Project are operated by The Hanna Mining Company in the vicinity of the towns of Keewatin and Nashwauk, on the western Mesabi Range. Production began in 1967, after seven years of exploratory and development diamond drilling and reconnaissance magnetic surveys, Previously, direct shipping hematitegoethite ores and gravity concentrates had been produced in the area from numerous open pits and several underground mines since the start of the century. Total shipments of these oxidized ores amounted to more than 200 million tons, but at the present time such reserves are nearly exhausted, and there are no mining operations in the Keewatin-Nashwauk area except at the two taconite projects. The locations of all of the present taconite operations on the Mesabi Range are shown in Figure 1, extending for a distance of about seventy miles from the Butler plant to the Dunka River area. The Butler and National plants have a combined rated capacity of 4.4 million tons of pellets. Their reserves cover a combined strike length of about eight miles on the Biwabik iron formation. All of the intervals between present taconite operations on the Mesabi are potential sources of additional magnetic taconite; in particular, exploration and economic studies have been carried out by Jones and Laughlin Steel Corporation in the Biwabik area between Aurora and Virginia, and by Pickands Mather and Company in the Hibbing area. However, west of the Henna and Butler holdings, it appears unlikely that magnetic taconite exists in commerical quantities at economic depths due to extensive oxidation of magnetite to hematite.

Jan 1, 1968

By N S. Weerasekara, S Town, E Lessing, J A. De Torres

Philsaga Mining Corporation (Philsaga) had three main aims in converting their lining system from steel to metal cap. They wanted to increase mill availability, minimise localised high wear and optimise particle breakage to deliver increased efficiency within the milling circuit. Combining Discrete Element Method (DEM) modelling and empirical interpretation of liner wear resulted in a rigorous approach to understanding the impact of mill liners on overall mill performance. This new understanding was subsequently used to not only derive a new lining design to optimise performance and thereby improve overall plant economics, but also to guide further lining development.In this work, detailed DEM modelling, developed from actual plant data, together with optimising liner design for wear paved the way towards the installation of a Metal Cap lining system at Philsaga’s Ø6100 mm SAG Mill. The results were a reported increase in SAG mill throughput of 16 – 20 per cent due to improved breakage through more efficient use of installed power, a reduction in localised high liner wear with overall increase in liner life and reduction in liner replacement time. Site also reported an increased gold recovery of 2 per cent which the improved breakage might have contributed to. This paper will present the design challenges and compare the Metal Cap lining systems performance against Steel lining system. CITATION:Weerasekara, N S, Lessing, E, Town, S and De Torres, J A, 2018. Metal cap versus steel lining system at Philsaga Mining Corporation’s Ø6100 mm SAG mill, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 653–664 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By J Webster-Brown

The Tui Mine is an abandoned Pb-Zn mine giving rise to water quality problems in the Te Aroha region of Coromandel, New Zealand. When sampled in September 2002, for example, both the Tui and Tunakohoia Streams draining the mine site exceeded ANZECC (2000) water quality guidelines for aquatic life protection (Cu, Cd and Zn) and recreational quality (Cd). Based on trace metal mass flux (kg/yr) from parts of the mine site, the principal pathways by which Cu, Zn and Cd contamination reach these streams have been identified as:the tailings dam leachate,the diverted stream water from above the dam,the drainage from Adit 5 (which accounts for 95 % of Zn and Cd contamination in Tunakohoia Stream), andto a lesser extent, run-off from waste rock piles below Adit 4 level. Of the various remediation options, which have been proposed for the site, the following are identified as providing the best protection for the Tui and Tunakohoia streams:stabilising the tailings dam embankment and capping the embankment and tailings,constructing and/or cleaning out engineered diversion drains around the perimeter of the tailings dam to divert surface water away from the tailings dam, andinstalling bulkheads within Adit 5. A formal postal survey of the people of Te Aroha (66 respondents from 230 surveys) indicated that their priority was that the site be made safe for the public to visit, and used for recreation. As soil samples in potential recreational areas of the mine site, significantly exceeded guideline values for Cu, Pb, Zn, Cd and As, soil removal or capping clearly also needs to be part of a remediation plan. Development of the site as a historical/ecotourism area was viewed favourably, as this may encourage more visitors to the Te Aroha area as well as educate local residents.

Jan 1, 2003

By W. J. Long

As a part of the strategic mineral exploration program, examining engineers of the Bureau of Mines collected samples of ore from four manganese properties in Yavapai, Yuma, Maricopa, and Mohave Counties, Ariz. As all of the ores were too low in grade to be acceptable by manufacturers of ferromanganese beneficiation studies were made to determine the amenability of the ores to concentration.

Jan 1, 1948

This paper examines the issues involved in the technical audit and valuation of exploration prospects. Certain methodologies are more appropriate to use depending upon whether the mineral property valuation is of an exploration area, a project under development, or an operating mine. Valuation approaches that are reviewed include the Multiple of Exploration Expenditure, Joint Venture Terms, Rules of Thumb, and particularly the Kilburn Rating Method. The DCF/NPV Financial Simulation Method, even modified by the use of Expected Values, is not considered appropriate for valuing exploration prospects. The choice of the most appropriate methodology and its successful application depends primarily upon the amount of reliable input data available and, more importantly, the experience and judgement of the valuer. It must be remembered that all valuations are time and circumstance specific and will be generally subject to revision as more data becomes available.

Jan 1, 1993

The authors have succeeded in providing additional rigour and clarity to the formulation and execution of the dynamic programming algorithm for optimum open pit limit determination. The inclusion of the blocks on the J + 1 column in the search for Pmax, and constraining this search with blocks assigned a value of negative infinity, ensures an optimal solution within the defmed blocks. The effect of the negative infmity blocks is to preclude mining along the diagonal blocks from the first row that they occur in. Figure 1 graphically illustrates the effects of this on the calculation of P. A practical application for constraining mining with negative infmity blocks is the case where the pit outline is defined by lease boundaries and not by the value of blocks to be removed. Any legal, social or physical constraint could be accounted for in the same way.The danger in applying this technique is that the negative infinity blocks will override any other more profitable solutions that may exist. This is in fact what has happened in the example that the authors use. If a further column is added to the left hand side (column -1) and the calculation is carried out again, a more optimal x-section can be found. (If the negative infinity values are removed the same result is obtained.) This gives a pit value of 112 as against the 108 of the authors' optimal pit. This calculation is shown in Figure 2. Lerchs-Grossman optimization is reliable only if there are sufficient columns available to allow "mining" to optimum depth of the ore body and still allow the pit to break out at the surface within the confines of the columns.This author's approach is to create enough columns each side of the lateral limits of the ore to allow the pit to intersect the surface while still within the confines of the block model. Implementing the methods discussed by the authors helps to reduce the number of columns required to achieve this.

Jan 1, 1987

Current mine production planning, scheduling, and allocation of resources are based on mathematical programming models. In practice, the optimized solution cannot be attained without examining all possible combinations and permutations of the extraction sequence. Operations research methods have limited applications in large-scale surface mining operations because the number of variables becomes too large. The primary objective of this study is to develop and implement a hybrid simulation framework for the open pit scheduling problem. The paper investigates the dynamics of open pit geometry and the subsequent material movement as a continuous system described by time-dependent differential equations. The continuous open pit simulator (COPS) implemented in MATLAB, based on modified elliptical frustum is used to model the evolution of open pit geometry in time and space. Discrete open pit simulator (DOPS) mimics the periodic expansion of the open pit layouts. Function approximation of the discrete simulated push-backs provides the means to convert the set of partial differential equations (PDEs), capturing the dynamics of open pit layouts, to a system of ordinary differential equations (ODEs). Numerical integration with the Runge-Kutta scheme yields the trajectory of the pit geometry over time with the respective volume of materials and the net present value (NPV) of the mining operation. A case study of an iron ore mine with 114 000 blocks was carried out to verify and validate the model. The optimized pit limit was designed using Lerchs-Grossman?s algorithm. The best-case annual schedule, generated by the shells node in Whittle Four-X yielded an NPV of $449 million over a 21-year mine life at a discount rate of 10% per annum. DOPS best scenario out of 2 500 simulation iterations resulted in an NPV of $443 million and COPS yielded an NPV of $440 million over the same time span. The hybrid simulation model is the basis for future research using reinforcement learning based on goal-directed intelligent agents.

Jan 1, 2008

By Edward A. Loria

A SERIES of papers on the study of austenite grain A size in cast steels has been published recently.'" These studies show that in the as-cast state, the austenite grains are quite large, for they form as the steel freezes at a very high temperature, but a simple reheating above the critical range produces a new set of austenite grains which, in many instances, is finer than ASTM grain sire No. 8. Furthermore, there is no apparent relationship between as-cast austenite grain size and subsequent grain size produced by heat treatment. The as-cast austenite grain size can be determined easily in plain carbon and low alloy steels which produce a continuous grain boundary f errite envelope in the as-cast structure. In the case of cast steels whose alloy content produces greater hardenability and suppresses the proeutectoid ferrite transforma-

Jan 1, 1952

By P. M. Robinson, M. B. Bever

THE heats of formation at 273°K of the compounds InBi, In2Bi, and TIBi2 have been determined by metal solution calorimetry with bismuth as solvent. The published information on the thermody-namic properties of these compounds is limited. The structure of the compound InBi (mp, 383°K) is tetragonal of the PbO (B10) type.1 The compounds In2Bi (mp, 362°K) and TIBi2 (mp of highest-melting composition, 486°K) are now believed to have structures of the NizIn (B8) type273 and not the A1B2 (C32) structures reported earlier.4, 5 The compounds In2Bi and TIBi2 have limited homogeneity ranges at room temperature, while the compound InBi has no detectable homogeneity range.' Samples of the compounds were prepared from 99.99 pet Bi (Mallinckrodt Chemical Works), 99.999 pet in (American Smelting and Refining Co.), and 99.99 pet Tl (Amend Drug and Chemical Co.) by melting the components in sealed, evacuated Vycor tubes. The compounds InBi and in2Bi were of the stoichiometric compositions. The compound TIBi2 contained 40 pet T1; this composition was chosen because at room temperature the alloy of stoichiometric composition does not lie within the homogeneity range.' The melts were held approximately 50°C above the liquidus for 8 hr and then quenched into iced brine. The samples were homogenized for 48 hr at temperatures 20°C below the temperature of complete solidification. Metallographic examination of sections taken from the center and the ends of the ingots did not reveal second phases or segregation . The heats of formation were determined as the difference in the heat effects on solution of a compound and of a mechanical mixture of its components added from the reference temperature of 273°K to liquid bismuth at 623°K. The details of the calori-metric procedure and method of calculation have been described elsewhere? The calorimeter was calibrated by adding bismuth at 273°K to the bismuth bath at 623°K. The calculated values of the heats of formation of the compounds, listed in Table I, are based on a value of 4.96 keal per g-atom for the difference between the heat contents of bismuth at 273" and 623oK7 No published values are available for the heats of formation of the compounds InBi and In2Bi. Hultgren et a1.7 have calculated a value of -0.50 i 0.10 keal per g-atom for the heat of formation at 423°K of the compound TIBi2 containing 40 at. pet T1 from heat-content measurements in the range from 398" to 700°K and the heats of formation of the liquid alloy. The difference between this value and the value of -0.66 * 0.01 keal per g-atom at 273°K is too large to be attributed to a difference between the heat capacities of the compound and the components over the temperature range 273o to 423oK7 However, the direct determination of the heat of formation by a calorimetric method should give a more accurate value. The heats of formation at 273°K of the compounds InBi and In2Bi lie on a straight line when plotted as a function of composition, Fig. 1. The compound In2Bi, therefore, appears to be barely stable with respect to its neighboring phases. In order for the free energy vs composition curve to be concave towards the composition axis, the entropy change on formation of In2Bi must be more positive than that on formation of InBi. As the compounds are ordered,2, 3, 8 there is no configurational entropy change on formation. The difference between the entropy changes on formation of the two compounds, therefore, is probably associated with the vibrational entropies. In view of the low heats of formation, the changes in vibrational entropy, due to changes in bond strength on formation of the two compounds, are likely to be small. Owing to the volume contractions on formation of the two compounds,5 the vibrational entropies probably decrease slightly but the decrease of the vibrational entropy of InBi is expected to be larger than that of In2Bi.

Jan 1, 1965

By F. W. Davis

This paper deals in a general way with certain of the necessary requirements of refractories for the open-hearth furnace. The refractories in common use for the different parts are discussed both as to the service they are giving and their suitability to withstand existing chemical, thermal and physical requirements. The relation between the service and allowable cost of a refractory is discussed and suggestions are requested on these points. The purpose of this paper is not to report, to the Institute, the results so far obtained in the survey, by the Bureau of Mines, of the metallurgical requirements for open-hearth refractories, but to present an outline that we hope will serve as a basis for discussion. The systematic survey that the Bureau proposes to make has not been outlined, although considerable preliminary work has been done in the way of interviewing open-hearth superintendents in several of the larger steel plants from the Chicago district eastward. At the several conferences so many of the opinions were diametrically opposite, when considering the same point, that it was thought that such an opportunity as the Institute offers in the way of a clearing house for moot metallurgical topics should not be overlooked. For this reason, the paper has been prepared as a basis for a discussion which, it is believed, will be of value in outlining the program of the Bureau. D. A. LYON, Assistant Director. THE importance of securing suitable refractories for metallurgical operations is daily becoming more universally recognized; particularly in the manufacture of open-hearth steel, where the life and earning power of the furnace depends largely on the judgment and care exercised in the selection of the correct quality of refractory for each of the parts. Any innovation that would make available to the steel manufacturers refractories with longer life or better suited to their needs than those now employed, and at a cost that would permit of their use, would be of enormous value to the industry at large. It is quite probable that revolutionary changes would not be necessary. Material now used in some parts of

Jan 3, 1924

By Andrew L. Puwis

Methodologies were presented for computing the thermal gradient associated with single crystal solidification in macroscopic computer modeling. The. heat transfer, and solidification of a shaped investment casting model were simulated using properties from three different alloys. Following the simulation of solidification, the resultant thermal gradients (G) and rates of solidification (R) from representative points were extracted in various ways and compared: It was discovered that alloy properties have a strong influence on the computed thermal gradient and rate of solidification for the three methods investigated. Data also showed that the computed gradient for each model was very different depending on the temperature range used to compute these values.

Jan 1, 1994

By Robert Head

El presente texto señala las probables tendencias de la industria cuprífera a lo largo de esta década, donde los pronósticos de una parte se basan en los hechos y datos del pasado, tanto de producción como de consumo. En cuanto la producción futura, ésta se basa sobre disminuciones en minas cuyas reservas se agotan, incrementos de minas en plena vida y minas nuevas o probables que serán llevadas a la producción a través de la década. Como consecuencia de esta posición de adecuado abastecimiento la tendencia a investigar por materiales en sustitución del cobre puede ser reducida. Asimismo, la nueva de producción vendrá de minas más grandes, de baja ley que necesitarán grandes inversiones de capital.

Mar 1, 1971

By Jean-Pierre Hamelin

Ground movements induced by underground excavation are always of critical concern, particularly in urban areas. Compensation grouting now appears as a safe means to control these movements. The paper presents new advanced systems developed by the specialist contractor to bring, at all stages of the project, an efficient control of operations and presents a case history taken from the project at Tren Urbano, Rio Piedras Section, constructed beneath an historic commercial section of San Juan de Puerto Rico.

Jan 1, 2000

By Arthur S. Wright

THE accuracy of the silver-assay depends in great measure upon a careful regulation of the heat of the muffle during the process of cupellation. At the beginning of the operation, a relatively high temperature is required to " open " the lead buttons, that is, to clear off the black film of oxide that covers the surface of the metal button immediately after fusion has taken place. The muffle is usually closed up until the buttons are uncovered. As soon as a clear, free surface of molten metal is exposed to the oxidizing action of the air, the temperature should immediately be lowered to the minimum temperature at which the formation and absorption of litharge can progress freely, and the buttons still be kept from " freezing." The process, under satisfactory conditions, will be characterized by the formation of rings of litharge crystals (" feathers," as they are styled), on the cupel, about the oxidizing globule; and the nearer these rings of litharge crystals call be made to approach the central oxidizing globule without interfering with the freedom of oxidation and absorption, the smaller will be the volatilization of silver, and consequeiltly the greater the degree of accuracy attained. This minimum heat must be maintained uniformly during the oxidation of the lead; and just as the last of the lead is disappearing, and the button is preparing to l blick," the temperature of the muffle should be allowed to rise so that the last traces of lead will be driven off. This regulation of the heat calls into play all the skill of the assayer, and requires a vigilant eye, able to distirlguish between the slightest variations of temperature of the muffle, assisted by a nice adjustment of fuel and draft. With a few cupels in the muffle at one time, the proper heat for each cupel can be maintained by roughly approximating the proper temperature, and then moving the cupels backward and forward in the muffle; but this is gene-

Jan 1, 1897

By N. T. Rempe

Proper use of natural resources is multiple use. Underground space resulting from mineral extraction offers opportunities for deep geologic waste disposal (DGWD) which can solve many environmental problems. U.S. government projects plan to use specially mined excavations to dispose of radiotoxic and mixed waste. DGWD takes careful planning, technology transfer, and true partnership between waste generators and mine/repository operators. Using the experience, accumulated by domestic projects in preparation, and by foreign repositories in operation, U.S. mines can claim their rightful share of the growing market for DGWD.

Jan 1, 1996

By Stefan Mewes

Europe’s second-largest seaport has installed a new combi wall consisting of pipe piles, sheet piles and inclined shaft grouted piles to support it. The new Liebherr piling rig with swinging leader was used to drive shaft grouted piles into a very dense soil layer of sand with glauconite. The 60 m Liebherr swinging leader was suspended at an inclination of 45° via a suspension frame and suspension ropes from the crawler crane. This inclined installation of shaft grouted piles via freely hanging swinging leader, as used for this project, is unique in Belgium. Moreover, the pile length of 43 m is a novelty for this type of pile. Shaft grouted piles consist of a steel profile with a separate box-like pile shoe with an open top. A thin grout is injected via an injection pipe during driving and emerges just above the pile shoe. As the pile is driven further down, so compressing the ground, the space above the pile foot is immediately filled with grout under pressure. This piling system is ideally suited for the transfer of high tensile loadings. It is a method to increase geotechnical load-bearing capacity and to reduce negative skin friction during pile driving.

Sep 1, 2022