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By Kaushik Dey

Bord and pillar is the most predominant method of wining of coal in Indian underground coal mines. Development heading in coal mines often encounters roof stability problem and results in roof overbreak. Research on this reveals that the blast-induced ground vibration may have significant contribution in roof overbreak, especially, when solid blasting is carried out in the bord and pillar method. Solid blasting, in general, is associated with higher charge confinement due to lack of free face and generates higher ground vibration, which in turn results in excess overbreak.

Jan 1, 2008

By A. Ravi Kumar

A trench is a structure to accommodate fluid carrying pipelines for water, gas, petroleum products etc. Trench serves the purpose to haul the fluids in bulk over long distances safely and economically. Use of pipeline for moving oil and gas was essentially a post World War II development, but now it has acquired its own importance.

Jan 1, 2008

By Harsh Kumar Verma

Blasting off-the-solid is the most commonly used method during development of galleries in Bord and Pillar method of underground coal mining. In this method, only P5 explosives are used with permitted delay detonators in accordance with the safety requirements stipulated by the regulatory bodies. Delay detonators made with pyrotechnic delay compositions have inherent scattering in their delay timings. It is desirable to use precise detonators to achieve better fragmentation, less vibration and noise. Overlapping of delay period is undesirable from production as well as safety point of view.

Jan 1, 2008

By Larry Mirabelli, David Lilly

In 1777, the French naturalist, Georges Louis Leclerc, Compte de Buffon developed a statistical technique to estimate the width between two parallel lines by randomly throwing a needle at the two lines and counting the number of times the needle intersected one of the two lines. By knowing the length of the needle, the distance between the parallel lines could be estimated. This analysis was named the “Buffon’s Needle Problem”.

Jan 1, 2008

By Tapan Goswami, Lloyd Hain, Geoff Brent

For many years Ramp 24 at Ensham mine in Queensland, Australia has suffered substantial coal loss and damage due to the fragile nature of the coal and problematic geological conditions, which have proved very challenging. In the past various blasting techniques were applied in attempts to improve coal recovery. One approach was to use a shallow throw (cast) blast followed by a separate post-strip blast underneath. Another method was the introduction of the practice known as “baby decking” with the addition of a large buffer of material in front of the coal. However, despite increasing mining costs, none of these techniques adequately reduced coal edge loss and damage.

Jan 1, 2008

By E. R. Spencer

National Institute for Occupational Safety and Health (NIOSH) researchers conducted an investigation to quantify sound levels and to determine the amount of sound reduction provided by engineering noise controls installed in a talc processing plant. Baseline sound level and sound intensity measurements were performed at the plant and the measurement locations were recorded for comparison to post-control measurements. Follow-up measurements were then made at the same locations after the initial noise controls were installed. The plant subsequently decided to implement additional noise controls and the researchers returned to conduct measurements for a final analysis of all noise controls. The most significant results showed a sound level reduction in the main mill area from a range of 93-104 dB(A) down to 90-94 dB(A), and a total sound power level reduction of 21 dB(A) for air classifying mill 3.

Jan 1, 2008

By Andrew J. Ciancia

The construction of the Pennsylvania Station in Manhattan, the Beaux-Arts masterpiece, was completed in 1910. In financial ruin, the Pennsylvania Railroad Company sold the station in the 1960?s and the new Madison Square Garden and the Penn Plaza complex were constructed at the site. The demolition of Pennsylvania Station brought public awareness and outcry to protect historic structures and the Landmarks Preservation Commission (LPC) was subsequently established in 1965. In the 1960?s relatively little engineering data was available on the performance of historic structures during adjacent construction and thus, no published criteria were established by the LPC on allowable movements and vibrations. During the late 1970?s a commercial tower was planned adjacent to the landmark Fraunces Tavern Block (FTB) in lower Manhattan. Through negotiations between the LPC and the developer, Dr. M. I. Esrig and the author were retained to monitor the historic block during foundation construction. The monitoring data and building performance compiled from the project formed the basis of the published 1981 ASCE technical paper by Esrig and Ciancia entitled ?The Avoidance of Damage to Historic Structures Resulting from Adjacent Construction?. Based on the ASCE paper, the NYC Department of Buildings adopted Technical Policy and Procedure Notice #10/88 entitled ?Procedures for the Avoidance of Damage to Historic Structures Resulting from Adjacent Construction When Subject to Controlled Inspection by Section 27-724 and for Any Existing Structure Designated by the Commissioner?, June 1988. This paper describes the author?s recent experience during the installation of deep foundations within, or adjacent to, three Manhattan landmark structures. Discussions are provided on the foundation construction, monitoring programs and performances of the three structures.

Jan 1, 2008

By Cissé Kane, Klaus Hieronymi, Mathias Schluep, Gerry Newson, Susanne Dittke

"E-waste is currently the fastest growing waste stream in South Africa as well as in many other African countries. Informal collectors, dismantlers and recyclers based in Africa play an increasingly larger role in the processing of e-waste under generally unacceptable social and environmental conditions. In direct response to this trend, and as part of Hewlett Packard’s international Extended Producer Responsibility, the project “e-Waste Management in Africa” was started in 2007 in cooperation with the Global Digital Solidarity Fund (DSF) and the Swiss Federal Laboratories for Materials Testing and Research (Empa). This project is investigating the e-Waste situation in various African Countries, including South Africa, while actively supporting the development of practical, socially just and environmentally acceptable local e-waste management solutions. To this end, the project has been funding the development of a pilot project in Cape Town, South Africa since February 2008, supporting the start-up of a low tech/highly labour intensive material dismantling and recovery facility (MRF) for the pre-processing of e-waste. The aim is to test the feasibility of an integrated value adding local e-Waste management system, designed to maximize the potential of refurbishment, repair, re-use, dismantling and recycling of equipment, with environmentally responsible disposal as a last resort only. The project also seeks to incorporate the current informal e-waste processing activities, by transforming them into sustainable and environmentally sound operations. The MRF acts as a nucleus, raising awareness, and providing training and education to previously disadvantaged individuals as a means of creating opportunities for entrepreneurship in the technical maintenance, dismantling and waste-to-art project sectors."

Jan 1, 2008

By Hemraj Dangi, S. Murali, Bhisham Yadav, Mohini Saxena, P. Asokan

"Demonstration studies were carried on the use of fly ash as soil modifier and supplier of micronutrients to improve the agricultural productivity based on the process optimised at lab scale at Advanced Materials & Processes Research Institute, Bhopal. The field trials were conducted in Uttar Pradesh (North India) Orissa (South Eastern India) and Madhya Pradesh (Central India) under different soil and crop conditions. 100-650 tonnes of fly ash per hectare were applied depending upon the soil and fly ash characteristics. Both short and long term studies on impact of fly ash on soil and food quality were conducted. With the fly ash application, the edible yield of tomato, cabbage, potato, wheat, pea, onion, paddy, sunflower, maize etc., were increased from 12 - 46% as compared to the control soil where no fly ash was used. The crop response to various elements mainly heavy metals grown in soil and fly ash applied soil was found comparable to that of control, which are within the permissible limits and meet the food quality standards. The results of impact of fly ash on biotic and abiotic properties of soil, along with the quantity and quality of agricultural produces generated under pilot scale demonstrations in three different parts of India are discussed in this paper. The outcome of this work could act as guiding force for confidence building and to maximise the use of fly ash, generated from thermal power plants worldwide as one of the major mineral waste for agriculture purposes.IntroductionThe advantages of application of fly ash in terms of improvement of soil properties and crop yields have been published by various researchers in India and abroad. Attention is also given about the possible negative and beneficial impact of pond ash in agriculture due to presence of heavy elements, radioactive nuclides and plant nutrients in fly ash. It is evident from the analysis of Indian fly ash that the presence of heavy elements and radionuclides levels are comparable with normal soil. The positive impact that has been reported is with regard to germination, yield and crop growth. The significant impacts are: long term effect of heavy and toxic elements content of fly ash on soil and up take of these elements by plant. Pilot scale demonstration studies have been completed with varying soil crop-combination under different agro-climatic conditions showed considerable improvement in the productivity of cereals, oil seeds and vegetables."

Jan 1, 2008

By Rick Deschamps

A reoccurring problem with support of excavations in urban areas involves the placement of external support components like anchors or nails in right-a-ways, subway and utility setbacks, in areas occupied by adjacent structures, and within the property of non cooperative neighbors. Such a situation occurred for a project in Arlington, Virginia, which ultimately resulted in the preliminary design of a large footing supported cantilever retaining wall that was extremely costly and impractical to build. An innovative design alternate consisting of a series of vertical concrete elements (VCEs) supported by post tensioned tiedowns was proposed to the General Contractor and accepted by the owner. The VCEs were designed to serve as the main structural elements for both the temporary support of excavation system and the permanent wall. The VCE?s were constructed using single bite diaphragm wall panels oriented perpendicular to the excavation face including a rebar cage and tremie concrete. Threaded inserts were placed within the rebar cage to attach the cast in place exterior wall. Overall stability and lateral movement of the VCEs were controlled by high capacity vertical anchors embedded within the VCE. A detailed instrumentation program was installed to monitor the movements of the VCEs with relation to the excavation depth. The paper present the project case history by discussing the design concepts of the VCE, the construction approaches used to install them, the construction challenges encountered, and the performance of the unique system.

Jan 1, 2008

Research cruises dedicated to seafloor hydrothermal activity along the Kermadec arc first began with the Sonne-135 expedition in 1998. This was followed by the worldÆs first systematic survey for venting along an arc during the 1999 NZAPLUME I expedition. Since then, cruises dedicated to mapping plumes along the Kermadec arc include NZAPLUME II (2002), NZAPLUME III (2004) and ROVARK (2007). In addition, the manned submersible cruises SWEEP Vents (2004) and NZASRoF (2005) utilised the Shinaki 6500 and Pisces V, respectively, to sample in detail select hydrothermalsystems for mineralised samples, rocks and vent fluids. The ROVARK (2007) cruise was the first to deploy an autonomous underwater vehicle (ABE) along the arc which surveyed Brothers volcano at a far greater resolution than had been done previously by ships on the sea surface. While these expeditions have largely been led by GNS Science, together with its collaborators from National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory (NOAA/PMEL), significant contributions have been made by other groups from various nations, exemplifying the global interest in seafloor hydrothermal activity associated with intraoceanic arcs. This is an ASTRACT only. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By A. Longval, Q. Jiao, T. Shannon

In 2000, Xstrata Zinc (former Falconbridge Ltd.) Brunswick Smelter commissioned a modified lead blast furnace. Since then, efforts have been made to improve its operation in order to achieve optimal operation in terms of coke consumption, lead loss to slag, and improved environmental and hygiene conditions. This paper will review the important step changes in operational philosophy, undertaken since 2004, for the control of the blast rate, oxygen enrichment in blast, slag chemistry and charge level. Furthermore, a review of the improvements made in secondary materials consumed at the blast furnace will be made. This paper will also discuss the significant reduction of the frequency of accretion removal as a result of improved furnace operation.

Jan 1, 2008

By M. Holmes, R. Molnar, E. Norton, K. Baxter, J. Riordan

The Boleo Copper-Cobalt-Zinc-Manganese Project of Baja Mining Corp. is situated adjacent to Santa Rosalia on the Baja Peninsula of Mexico. The El Boleo ore is a mixed oxide-sulfide deposit with major values in copper, cobalt, zinc and manganese. The metallurgical process designed to treat the El Boleo orebody involves a sulfuric acid leach in seawater using oxidative and then reductive leaching to maximize metal extraction. The leach solution is separated from the barren solids via counter current washing through a series of high rate thickeners. Copper is recovered using conventional SX-EW processing as cathode. Zinc and cobalt are extracted from the copper SX raffinate after iron and aluminum precipitation. The CSIRO DSX solvent system (Versatic® 10 and LIX® 63 mixture) are used in this extraction. Manganese remains in the DSX raffinate and is recovered by soda ash addition as a high quality manganese carbonate precipitate. Zinc and cobalt are acid stripped from the loaded DSX solvent. Zinc is then re-extracted away from cobalt using Cyanex® 272 extractant and stripped into a highly concentrated strip liquor (+100 g/L Zn) and directed to either a spray dryer or a granulator for production of zinc sulfate monohydrate. The zinc solvent extraction raffinate, containing cobalt, advances to another SX circuit using Cyanex® 272, for the recovery of cobalt as cobalt cathode. In this paper, the detailed results from bench and integrated pilot plant testing for zinc recovery from the El Boleo ore will be described. The results of this testing are currently being used to engineer the commercial plant at El Boleo.

Jan 1, 2008

By Dennis R. Dolinar

The National Institute for Occupational Safety and Health?s Pittsburgh Research Laboratory conducted a full-scale test of a composite polyurethane-aggregate seal in a hydrostatic chamber at the Lake Lynn Experimental Mine. This composite seal consisted of a polyurethane and limestone aggregate core that was formed between two concrete block walls. In the hydro-static chamber test, water is used to pressurize the seal. During the test, the maximum average water pressure the seal was able to withstand was 18.9 psi. Further, the seal began to yield at an average water pressure of only 17 psi. At the time of the test, the minimum seal design requirement was 20 psi under 30 CFR4 75.335 (2005). Therefore, based on this test, the seal did not meet the regulatory minimum design requirement. Uniaxial compressive tests conducted on samples from the polyurethane-aggregate core revealed that both the compressive strength and the elastic modulus of the material were much less than that for polyurethane only with a density of 10.0?12.0 lb/ft3. The significant reduction in the strength and stiffness of the polyurethane-aggregate mixture results from the formation of a soft polyurethane foam around each piece of aggregate. The formation of the soft foam seems to be caused by residual moisture from the aggregate. The moisture also caused the density of the polyurethane in the polyurethane-aggregate mixture to be less than the design requirements. The lower density of the polyurethane in the mixture, along with the formation of zones of pure polyurethane only, resulted in the overall seal density being less than the design requirements. During seal construction, steps were taken to control the moisture, but were not successful. An analysis of the seal failure showed that the calculated shear stresses at failure and the estimated shear strength of the polyurethane-aggregate mixture are fairly close. This suggests that the strength properties of the polyurethane-aggregate mixture along with a weak zone of poorly bonded aggregate controlled the maximum pressure the seal could withstand. At the time of the seal testing, the minimum design requirement was 20 psi, as specified at 30 CFR 75.335 (2005). New emergency temporary standards for seal designs were promulgated on May 22, 2007, with a minimum requirement of 50 psi under specified conditions. However, it will be shown that the evaluation of the polyurethane seal performance as designed to meet the older 20-psi criterion can be relevant to the design requirements under the new standards.

Jan 1, 2008

By Eric S. Weiss

The National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) conducted joint research to evaluate explosion blast effects on typical U.S. mine ventilation stoppings in the NIOSH Pittsburgh Research Laboratory?s (PRL) Lake Lynn Experimental Mine (LLEM). An innovative Australian-designed brattice stop-ping was also evaluated. After mine explosion accidents, MSHA conducts investigations to determine the cause(s) as a means to prevent future occurrences. As part of these postexplosion investigations, the condition of underground stoppings, including the debris from damaged stoppings, is documented as evidence of the approximate strength and the direction of the explosion forces. The LLEM data showed that a typical dry-stacked and coated solid-concrete-block stopping survived a total explosion pressure of ~6.7 psi (~46 kPa) and was destroyed at a total explosion pressure of ~7.6 psi (~52 kPa). In comparison, a typical dry-stacked and coated hollow-core concrete block stopping survived a total explosion pressure of ~3.4?4.3 psi (~23?30 kPa) and was destroyed at a total explosion pressure of ~3.6?5.2 psi (~25?36 kPa), depending on the length of the pressure pulse and the value of the pressure-time integral. A typical steel panel stopping design survived a total explosion pressure of 0.8 psi (5.5 kPa) and failed at a total explosion pressure of 1.3 psi (9 kPa). The LLEM data also showed that an obstacle blocking the path of a pressure wave resulted in a higher reflected pressure at the obstacle. An 8-in (20-cm) thick wet-laid solid-concrete-block stopping coated on one side survived a total explosion pressure of ~26 psi (~180 kPa); this stopping was not tested to failure. A 6-in (15-cm) thick wet-laid solid-concrete-block stopping coated on one side survived a total explosion pressure of ~14 psi (~97 kPa) and was destroyed at a total explosion pressure of ~25 psi (~172 kPa). An innovative Australian woven cloth stopping survived an explosion pressure of 4.0 psi (27 kPa) and was destroyed at an explosion pressure of ~6.1 psi (~42 kPa). These results will help investigators determine the approximate explosion forces that destroy or damage stoppings during actual coal mine explosions.

Jan 1, 2008

By John A. Organiscak

Enclosed cabs are a primary means of reducing equipment operators? silica dust exposure at surface mines. The National Institute for Occupational Safety and Health experimentally investigated various factor effects on cab air filtration system performance. The factors investi­gated were intake filter efficiency, intake air leakage, intake filter loading (filter flow resistance), recirculation filter use, and wind effects on cab particulate penetration. Adding an intake pressurizer fan to the filtration system was also investigated. Results indicate that intake filter efficiency and recirculation filter use were the two most influential factors on cab penetration performance. Use of the recirculation filter reduced cab penetration by usually an order of magnitude over the intake air filter alone because of the multi­plicative filtration of the cab interior air. Intake air leakage and filter loading affected the cab penetration to a lesser extent, while wind had the least impact on cab penetration between the calm and 10-mph wind velocities tested. Adding an intake pressurizer fan notably increased intake airflow and cab pressure with only minor changes to cab penetration. A mathematical model was developed that describes cab penetration in terms of intake filter efficiency, intake air quantity, intake air leakage, recirculation filter efficiency, recirculation filter quantity, and wind penetration.

Jan 1, 2008

By Kim Verbeken, Evelien Van de Steene, Marc Verhaege, Jeriffa De Clercq

"AbstractThe industry is confronted with stricter discharge levels and an increasing awareness to avoid toxic waste (such as heavy metal containing sludge obtained in physicochemical water treatment) and recover valuable metals. This can be realized by ion exchange or by electrodeposition. Both techniques however show an optimum concentration range to efficiently remove and/or recover metals: electrolysis can recover the metal in its metallic form but suffers from low efficiency when applied to diluted solutions, whereas ion exchange can only be applied economically in the low ppm range.A combination of ion exchange followed by electrodeposition was applied to an industrial wastewater. The strong acidic ion exchange resin was stripped with H2SO4 giving a solution of 9g/L nickel. From this solution, nickel was electrodeposited in an ammonia buffer on a Ti-mesh cathode with high current efficiency. It is shown that organic compounds (surfactants, brighteners, …) present in the industrial wastewater do not influence the recovery process.IntroductionAlmost all rinse waters emerging from metal plating plants are generated during the washing operation of plated materials. These solutions with low metal content must either be recycled within the process or be discarded to the surface water after decreasing their metal content to acceptable levels determined by the local environmental regulations, which become more and more stringent. Today, the most commonly used practice is a physico-chemical treatment (precipitation) and a resin post treatment to meet the standards. A more sustainable approach should use a technology to recover efficiently the metal or metal salt without the production of sludge and the effluent should be consistent with environmental regulations."

Jan 1, 2008

By Carlos Maurício Fontes Vieira, Sergio Neves Monteiro, Diogo Neves Henriques

"This work evaluates the effect of incorporation of an ornamental rock waste into an industrial clayey body used for roofing tiles fabrication. Formulations with 0, 10, 20 and 30 wt.% of waste were prepared by replacing the sand in the industrial clayey body. The plasticity of the formulations was determined by the Atterberg limits. Specimens were fabricated by 18 MPa press-molding and then fired from 850 to 1100oC. The specimens were tested to determine the water absorption, linear shrinkage and three points bending flexural strength. The results indicated that the waste improves the extrusion performance of the clayey body by decreasing its plasticity. The use of the waste was beneficial to the water absorption and mechanical strength of the fired clayey ceramic at temperatures above 1000 ° C.IntroductionOrnamental rock is a natural resource available in the municipal area of Santo Antônio de Pádua and located 150 km from the city of Campos dos Goytacazes, northe of state of Rio de Janeiro, Brazil. Intense industrial activity related to ornamental stones, especially gneisses, is traditionally occurring in the region. After mining, the flagstone is submitted to sawing to obtain blocks and then, after a manual operation, the final products are small flagstones [1,2]. During the sawing operation, a sludge composed of water and fine particles of rock is generated. A monthly production of 1000 tons of ornamental rock waste is estimated to be produced at Santo Antônio de Pádua. The final disposal of this waste has brought serious environmental problems. Since most industries do not have an adequate sludge treatment, the waste is contaminating the soil and underground waters as well as obstructing rivers and lakes.Ceramic bodies industrially fabricated in the municipal area of Campos dos Goytacazes, 280 km from the city of Rio de Janeiro, are still empirically elaborated using a mixture of local clays. These clays are predominantly kaolinitic mineral, associated with high plasticity. Due to the excessive plasticity of the ceramic bodies, it is common to have dimensional defects in the final products after the drying and firing processes. Moreover, the kaolinitic structure and the presence of aluminum hydroxide confer a refractory behavior to the local clays. This impairs sintering during the firing operation. In the case of clay ceramics for civil construction, this results in greater porosity associated with elevated values of water absorption and low mechanical strength [3,4]. To avoid these problems, it is necessary to reformulate the ceramic body composition. The addition of both non-plastic materials to reduce plasticity and fluxes to condition the refractoriness is a possible alternative."

Jan 1, 2008

By Nicola Baldo, Marco Pasetto

"Recycling of tyre rubber in the road pavement, may be one of the best way to reduce waste tires in large quantities and, at the same time, improve some engineering properties of asphalt mixtures. The paper discusses the results of an experimental study, developed in order to analyse the potentialities of crumb rubber from road tyres in bituminous mixtures, using the dry process. Two types of porous asphalt mixtures and reference mixes without rubber were formulated by the traditional Marshall methodology, and mechanically evaluated by means of the Indirect Tensile Stiffness Modulus test, the Creep test (with confinement), and the Indirect Tensile Fatigue Test. Results of this study indicate that the tyre rubber has a positive influence on the performance characteristics, depending also on the grading and volumetric properties of the mix being studied: an interesting increase of the fatigue life, a better stiffness behaviour at lower temperatures and a bigger permanent deformation resistance at high temperatures are guaranteed. Introduction Recycling the rubber from used tyres, in the construction of road pavement layers, is potentially one of the more interesting and advantageous solutions from both the technical and environmental points of view, in order to reduce the total amount of car and lorry tyres to dispose. In road-building techniques, a technology, termed “wet”, for modifying bituminous binders with crumb rubber has by now become well consolidated. There have been numerous scientific studies conducted on this technology and its applications, particularly in the United States, where it has been adopted and codified in specific technical regulations (ASTM D-6114). If the wet process can be considered amply tested, the same cannot be said for a second technology, termed “dry”, which deserves careful study to evaluate its suitability and advantages. In “dry” processes, the rubber is usually used as a partial substitute of aggregate of equivalent grading and mixed with bitumen after integrating the crumb rubber in the lithic skeleton."

Jan 1, 2008

By M. Omneya El-Hussaini, M. Galal Abdel Wahab, A. Mohamed Mahdy, M. Fathi El Shahat

"Um-Gheig Pb-Zn representative sample was collected from the main adite of Um-Gheig mine along Red Sea coast in Egypt. Its chemical analysis shows that, it contains 16% Zn, 2.3% Pb, 0.1% Cd and 0.1% B as elements of interest. After H2SO4 agitation leaching, the chemical composition of Um- Gheig Pb-Zn deposit ore residue assayed 2.26% Pb, 1.5% Zn, 0.085 % B and 0.01% Cd. This residue was leached with 20% HCl at S/L ratio 1/3 for 2 hours at 80o C. The chloride leach liquor was found to contain 18 g/l Pb, 13 g/l Zn, 0.1 g/l Cd and 0.75 g/l B with the corresponding leaching efficiencies 79%, 86%, 100% and 88% respectively. Lead was precipitated from the chloride leach liquor using concentrated H2SO4 to obtain PbSO4 with precipitation efficiency 96%. While boron was extracted by the selective resin Amberlite IRA743 with loading efficiency of 80%. On the other hand, Zn and Cd were precipitated using Na2S solution with 86.7% and 100% recovery efficiencies respectively.IntroductionLead-zinc ores occur in Egypt in a few localities distributed along the Red Sea coast between El Qusier and Ras Banas.. The reserve of the ore deposits has been estimated by Soviet and German Experts to be about 900,000 Ton, [1]. Onal et al., [2] recovered Pb from Pb–Zn sample containing 10.17 % Pb and 10.98 % Zn from Aladag in Turkey. El-Sherif, [3] used concentrated HCl to leach lead-zinc ore sample of Um-Sammuki area in Egypt. As had been published by Marchioretto et al. [4], the precipitation of heavy metals with lime, sulfide and caustic soda are the most commonly used economical methods for metal removal. Lead was completely removed from the anaerobically digested sludge by precipitation with NaOH and Na2S at waste water treatment plants. Mahdy et al., [5] had successfully extracted boron from the bittern solution of Qaron Lake by ion exchange resin (Amberlite IRA 743). The extraction of boron was mainly depending upon the pH value. They extracted 80% of boron at pH 5.5, while at pH 3.9 about 74% boron was extracted. Kabay et al. [6] used the column-mode to remove 1g/l of boron from geothermal waste water of the Kizildere-Geothermal Power Station by using Diaion CRB 02 Nglucamine- type chelating resins. In this regard, the removal of lead, cadmium and boron allow the residue to be reclassified as non hazardous material."

Jan 1, 2008