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By F. S. Hoseinian, M. Irannajad, M. Safari

In this study, the effect of chemical interactions of materials used in ion flotation on the removal of Ni(II) ions from low concentration synthetic wastewater was studied. Sodium dodecyl sulfate (SDS) and ethylhexadecyldimethylammonium bromide (EHDABr) as collectors and methyl isobutyl carbonyl (MIBC) and Dowfroth250 as frothers were used. To investigate the effective parameters and interactions of them, 16 experiments including 6 level variables were performed by supporting DX7 software and on the bases of 2-level factorial method. In the first step, the tests were conducted in a Hallimond tube. The result showed that collector of SDS and frother of Dowfroth 250 had appropriate interaction with each other at pH = 3. In the second step, optimal results from the first step were evaluated in a mechanical flotation cell. The removal of Ni(II) ions increased by increasing the time of flotation and they have a direct relation with the water removal. The kinetics study shows that the order and the rate of removal of the reaction do not follow any of the zero-order, first-order and second-order equations. The flotation rate curve on the removal of Ni(II) ions will divide the separation process to two stages, a fast flotation rate at the first stage and a slow flotation rate at the second stage. Ni(II) ions removal was obtained 88% at the best condition.This study showed that the use of ion flotation was a very effective method for Ni(II) ion removal from industrial wastewaters.

Jan 1, 2016

By Xiaoxing Hu, Guibing Zheng, Yangge Zhu, Xingrong Zhang

"In China, more than 90 percent of titanium resources are reserved in vanadic titano-magnetite deposits. In this type of ore, the same elements such as Ti, Fe, Ca, Mg exist on surface of both ilmenite and titanaugite (the gangue mineral) because of isomorphism, which makes selective flotation difficult. Therefore, how to enlarge the floatability difference between these two minerals has always been a research emphasis and still needs to be studied further. In this paper, the pre-treatment methods using ultrasonic wave were proposed. The results indicate that ultrasonic treatment shows beneficial effect to enlarge the floatability difference, and the effect will be strengthened by extending the ultrasonic treatment time or increasing the ultrasonic power. The mechanism was investigated through infrared spectroscopic (FT-IR) analysis. Collector interacts with Ca and Mg which results in titanaugite flotation, after ultrasonic treatment, the dissolution of Ca and Mg is intensified, which leads to the lack of active points on mineral surface, so the floatability of titanaugite is depressed. Meanwhile, collector mainly interacts with Fe which results in ilmenite flotation, and the present of ultrasonic might promote its oxidation (Fe2+ to Fe3+), so the floatability of ilmenite after sonication is increased.INTRODUCTIONUltrasonic is the sound wave with frequency of 2 × 10-4 Hz~2 × 10-9Hz. Since the first International Symposium of Sonochemistry in 1986, the application of ultrasonic wave is more and more extensive. In researches about mining and metallurgy, various investigators have shown that intensive acoustic fields can modify the state of a mineral, leading to chemical or dispersive effects. Generally, the effect of ultrasonic vibration depends upon the nature of the mineral and also the way ultrasonic wave is applied (Celik, 1989; Ozkan, 2002). In addition, ultrasonic treatment usually plays roles of removal of reagents adsorbed layer from minerals and emulsification of flotation reagents when it is used in flotation (Nicol, Engel, & Teh, 1986; Slaczka, 1987; Djendova & Mehandj, 1992; Farmer, Collings, & Jameson, 2000; Gurpinar, Sonmez, & Bozkurt, 2004)."

Jan 1, 2016

By Y. Jiang, B. Li, R. Liu

"In this study, laboratory flow tests were conducted on 2-D artificial rock fracture network models containing a single intersection constituted by two inlet and two outlet branches. Three models with different intersecting angles of 60°, 90° and 120° were tested using both dye solution and distilled water. Constant flow rates were imposed on one inlet, and the flow patterns in the fracture intersections were captured by using a CCD camera. The test results were compared with the predictions made by numerical simulations that solved the Navier-Stokes equations. The results revealed that when Reynolds number (Re) is as low as less than 1, the intersecting angle has negligible influence on the flow rate of each branch and the flow patterns within a fracture intersection. As the interesting angle ? and Re (e.g., from 10 to 200) change, the normalized flow rates of different outlet branches change significantly, due to the inertial effect of fluid flow. These changes could be represented by a series of mathematical expressions involving Re and ?, which could be applied to fracture network models to improve their prediction accuracy on hydraulic properties (e.g., permeability and breakthrough curves of particles) of rock masses. INTRODUCTIONCoupled stress, flow, heat and mass transport are the corner stone subjects for many geoscience and geo-engineering disciplines, such as geological disposal of radioactive waste and geothermal energy exploitation. Many outstanding issues need to be investigated to enhance the knowledge on these subjects, and specifically more in-depth research in testing and modeling of the fluid flow in fractured rock masses is needed. In recent years, discrete fracture network (DFN) models have been extensively used to study the fluid flow and mass transport behaviors of fractured rock masses (e.g., Min et al., 2004; Zhao et al., 2011). In these models, each fracture is usually represented by a parallel-plate model, in which fluid flow exactly follows the cubic law. Therefore, comparative flow rate in each outlet branch of an intersection in these models only depends on its aperture. In reality, due to the surface roughness of fractures, the magnitude of mechanical aperture is usually larger than that of the hydraulic aperture of each fracture (Li et al., 2008; Xiong et al., 2011), and abundant flow patterns could exist in an intersection, influenced by its geometry, varying with changing Reynolds number (Re) (Kosakoswski & Berkowitz, 1999). Recent studies have also revealed that different mixing patterns might exist at a fracture intersection, bounded between streamline routing model and complete mixing model, that determine the final distribution of solutes in fractured rock masses (Johnson and Brown, 2001; Park et al., 2001). Numerical simulation has been the principal method adopted in previous studies, and the studies conducting flow tests on intersected fractures are less reported (Wilson & Witherspoon, 1976; Johnson and Brown, 2001). In this study, laboratory flow tests and numerical simulations by solving the Navier-Stokes equations were conducted on 2-D models containing a single intersection constituted by two inlet and two outlet branches, intersected at different angles. The main objective is to study the influence of intersecting angle on the flow behavior of the intersected fractures and the variations of flow patterns and fluid redistribution in each model along with the changes of the Re and the intersecting angle ?. The influence of surface roughness was not considered."

Jan 1, 2015

By A. Scheltema Beduin, M. Kalisch, E. Floch, R. J. Dijkhuis, H. J. Oterdoom

In metallurgical copper production, the traditional aim is to increase recovery of copper to the maximum. SMS Siemag (SMS) has supplied numerous furnaces for this application. New targets are to make sure end of line products are as safe as possible with respect to health and environment, and to maximize raw material utilization. This means a for example a minimization of leachable metals in slag, so it can be safely used as a construction material, and either a targeted concentration or fixation of volatile compounds, such as arsenic. Currently, 2 process routes are generally applied for slag cleaning. The first is grinding followed by flotation, and the second is slag cleaning in an (electrical) furnace. Popularity of both options has fluctuated over the years, and currently the milling-flotation seems to be the more popular option. In this article some of the advantages and disadvantages of both methods are described, and especially how long term environmental policies could have an impact on the decision which process route to choose. Finally, this article will describe some of the developments SMS is working on in pyrometallurgical slag cleaning that could influence the direction for the design of the copper plant of the future.

Jan 1, 2014

By Z. Liang, Z. Q. Liu, X. F. Li, H. L. Zhang

"Dynamic characteristics of frozen soil is important for the safe, effective and rapid construction in cold regions and artificially frozen engineering. In this paper, dynamic characteristics of frozen clay with various low temperature and different strain rate were studied by using Split Hopkinson Pressure Bar (SHPB) test and numerical simulation test. Variation of dynamical parameters and dynamic stress-strain curves of frozen clay were obtained and analyzed. The results of these test show that: Frozen clay exhibits temperature effect and strain rate effect that the failure type tends from plastic failure to brittle failure with the increase of strain rate or decrease of temperature; Under impact loading, frozen clay exhibits three typical dynamic stress-strain curves as strain rate increases, and the maximum strain of frozen clay only linear increases with strain rate.INTRODUCTIONArtificial freezing technology has been widely used in the construction of underground engineering, such as the coal mine shaft, the deep foundation pit, the urban metro and subsea tunnel, etc. Research on dynamic mechanical behavior of artificial frozen soil will provide supports for these artificially frozen engineering (Xu et al. 1998; Ma 2009). However, the dynamic mechanical research on frozen soil is mainly carried out at low frequencies or small amplitudes of the waves, behavior of frozen soil under impact loads or high strain rate loads has not been made clear."

Jan 1, 2015

By Collin Bartlett, H. Storch

"Modern metallurgical processes operating with oxygen enriched air, such as the Outotec Flash Smelter and Flash Converter, generate very concentrated SO2 off-gas, which in combination with Outotec sulphuric acid plant technology allows the production of high pressure steam to be used for power generation. Outotec combines well proven technology of sulphur burning plants for this purpose with metallurgical plants.The application of Outotec’s proven LURECTM process enables processing of SO2 gas of up to 25 vol.-%. This process maximizes the energy recovery from the SO2 oxidation at a suitable high temperature level which can be turned into high pressure steam. The application of the Outotec HEROSTM heat recovery system enables the generation of low pressure steam from the absorption energy released at the intermediate absorption step. Additionally, energy is also recovered in the acid coolers for boiler feedwater pre-heating.The concept of integration of high and low pressure steam in combination with the pressurized operation of the boiler feedwater deaerator, thus heating up the boiler feed water to temperatures around 160…170°C, enables indirect transfer of low pressure steam (for deaerator operation) into more valuable high pressure steam, which improves the degree of heat recovery. This is the characteristic of Outotec’s HEROS+TM process.The increased generation of high pressure steam will in turn enable the generation of more electricity when compared to a standard traditional sulphuric acid process."

Jan 1, 2014

By A. Mortazavi, H. Nasab

"The storage of petroleum products on surface is associated with difficulties and limitations. Accordingly, a viable alternative is to excavate underground space in rock and provide a safe way for oil storage. Soft rocks such as salt domes provide good conditions from environmental and operational points of view. The potential for high-volume storage and low permeability are encouraging aspects for oil storage in salt domes. The complicated shape of oil storage caverns, the complicated behavior of salt rocks, and boundary conditions associated with large underground openings are important challenges in the design of oil storage caverns. The aim of this paper is to delve into the stability and deformation mechanisms of storage caverns created in salt domes. A parametric study of effect of the cavern size, orientation, and depth is carried out as a function of ground stress regime. The stress field and deformation mechanisms are calculated for each case aiming at providing design guideline.INTRODUCTIONOne of the most popular soft rock that is used for underground oil storage is salt rock (halite). Salt rock has particular characteristics which makes it suitable for oil storage. Salt rock has several advantages for oil storage, these are: high production rate, high degree of availability, short filling period, high level of safety and low permeability [1]. The low permeability is due to the fact that halite deforms in a plastic manner over a wide range of pressures, temperatures and rates of deformations. This property prevents joints or gaps opening up in the formation, thus preventing the escape of liquids and gases. The state of stresses around the cavern in salt domes depends on the depth of the cavern (initial stresses and rock mass temperatures are increasing with depth), the in-situ stress state within the rock mass, and the internal oil pressure in the cavern. Furthermore, the salt creep behavior and the cavern geometry are influencing stress redistributions during loading and unloading phases.Rock mass structure, cavern geometry, material behavior and cavern operation patterns require complex physical models to describe the load-bearing behavior of the geomechanical structure. The determination of stress, strain and deformation in the rock mass due to cavern construction and operation are complex problems which can be evaluated employing numerical tools such as the Finite Element Method (FEM) or Finite Difference Method (FDM). In this study, the finite difference method was used to evaluate the behavior of oil storage cavern in salt rock."

Jan 1, 2015

ABSTRACT The SART (sulphidization, acidification, recycle, and thickening) process is an effective way to separate copper and cyanide in the waste stream of gold processing plants using cyanidation. Factorial experimentation has been conducted to create models of copper recovery, cyanide recovery, acid addition, and oxidation/reduction potential during SART. Economic analysis of the resultant models showed that SART is best operated with a sulphide-to-copper molar ratio of approximately 0.56, pH of 4, and a minimized cyanide-to-copper molar ratio. The experiments also showed th0at residence time can have drastic impacts on SART performance.

Jan 1, 2013

By T. Gerritsen, T. Plikas, K. Ochoa, M. Loveless, R. MacRosty, J. Reichart, R. Pula

Sidewall accretion in a smelting furnace plays an important role in furnace integrity as it provides protection to the sidewall cooling elements and thereby extends the furnace campaign life. The extreme thermal and mechanical stresses in the furnace and changes in the slag chemistry can cause the sidewall accretion to melt or break away decreasing the lining protecting the cooling elements. Thin accretion is highly undesirable as it increases the risk of exposing the cooling elements to the molten bath and in the worst case may lead to a failure. Therefore, monitoring the sidewall accretion on an operating furnace is extremely important to manage furnace integrity and to support safe furnace operation. Operators often generate estimates for sidewall accretion and refractory thickness using either copper cooler temperatures or heat load into the cooling water circuits. Multivariate statistical models, on the other hand, have the capability to consider all the process measurements simultaneously to provide a more reliable estimate. This paper describes the application of multivariate statistical models for sidewall integrity monitoring on a Flash Converting Furnace (FCF) and also discusses the online implementation of these models as the Sidewall Accretion Monitoring System. INTRODUCTION Rio Tinto’s Kennecott Utah Copper (KUC) smelter located near Salt Lake city, Utah operates a Flash Smelting Furnace (FSF) and a Flash Converting Furnace (FCF) to produce high-grade matte and blister copper respectively. Since the commissioning of smelter in 1995, several improvements were made to these furnaces to increase their efficiency and operational safety. At present, Kennecott smelter is known to be among the lowest-emission and highest energy recovery copper smelters in the world. Since the smelter start-up, Kennecott has invested in several advanced furnace monitoring practices to evaluate the integrity of the furnaces and improve their campaign life. An example is their temperature monitoring system installed for the smelting and converting furnaces, which continuously monitors the furnace sidewall temperatures and notifies the operators during temperature excursions. During an investigation on the converting furnace, it was revealed that there were frequent temperature excursions in the settler sidewall area towards the reaction shaft end of the furnace that caused significant furnace downtime. The reason for the sidewall temperature excursions was not clearly known.

Jan 1, 2019

By R. Tremblay, M. Burrows

"In the summer of 1990, pilot scale testing of a Jameson cell was carried out at Falcon bridge Limited, Kidd Creek Division. The Jameson cell is self aspirating and has fewer mechanical parts, thus it has a lower operating cost compared to conventional cells. This lower operating cost combined with positive pilot scale results, justified the evaluation of two full scale cells in the plant. The plant test had two mandates:1. Gain a thorough understanding of the cells operation and design constraints.2. Develop a flow sheet to replace three divisions of copper cleaner flotation.This paper provides an overview on the installation, commissioning and evaluation of the two Jameson cells acquired. The current status of the test program is also discussed.IntroductionThe Falcon bridge Limited-Kidd Creek Division concentrator is located in Timmins, Ontario. The concentrator, commissioned in 1966 and expanded in 1978, consists of four parallel grinding and flotation divisions utilising small cell (60 ft3) technology. With increasing pressure to maintain low operating unit costs a series of studies were undertaken to assess the impact of new technologies in the flotation circuits. The goals of the project were to improve productivity through increased metallurgical performance and/or reduced operating costs.One of the technologies investigated was the Jameson cell designed by Dr. Graeme Jameson of the University of Newcastle and marketed by MIM Holdings Limited, Australia. This style of column technology was chosen based on its potential for reduced capital and operating cost versus large conventional cells.The success of pilot testwork in 1990 led to the installation of two production sized Jameson cells beginning in October 1991. The units were to be used to confirm pilot results and determine equipment requirements for flotation modernisation. This paper will discuss the results and experiences Kidd Creek has had with the Jameson cell from pilot scale through installation and commissioning of the plant units."

Jan 1, 1993

By M. H. Attia

The concept of sustainable development has been evolved into a working framework for sustainable manufacturing, in which the environmental requirements are introduced into product development at the design stage. This keynote paper is discussing a number of issues pertaining to the impact of manufacturing on the environment. The conflicting requirements of sustainable development, sustainable manufacturing (SM) and economical growth are presented in the light of successful case studies that were able to convert conflicts into opportunities. Integration of SM into the product life cycle is also presented. A number of concepts that are related to Ecoefficiency, e.g., inverse manufacturing, demanufacturing and re-manufacturing are also discussed. The paper underlines the fact that the positive impact of this new philosophy is equally applicable and beneficial to both; developed and developing countries. The paper concludes with an overview of Global trends in environmentally benign manufacturing (EBM); e.g., product-take back and emerging material and processing technologies. The state-of-the-art approach to Life Cycle Impact Assessment and integration of design for the environment DfE principles are demonstrated through some case study.

Jan 1, 2006

By J. S. Scott

"The Quemont property comprises 640 acres lying directly north of and adjoining the Noranda (Horne) mine. During 1926 to 1928, United Verde Extension Mining Corporation sank a shaft 235 feet and did 3,000 feet of development work on the 215-foot level. Between 1929 and 1930, Quemonr Mining Corporation deepened the shaft to 926 feet, and did further lateral work and drilling on the 500- and 900-foot levels. This work was confined to an area close to the south boundary and met with little encouragement.Following a period of idleness a magnetic survey was made in the winter of 1944, followed in the summer of the same year by some 6,000 feet of drilling. The first successful hole was drilled in February, 1945, from the ice of Osisko lake.To the time of writing, 131,000 feet of drilling, surface and underground,have indicated a large tonnage of gold-silver-copper-zinc ore, and although some knowledge of the geology and structure is emerging, it is too early to draw definite conclusions. The following brief description deals only with those structural features that are reasonably well indicated."

Jan 1, 1954

By S. Fox, Y. Fujita

Increasing demand for rare earth elements (REE) is expected to lead to new development and expansion in industries processing and or recycling REE. For some industrial operators, sending aqueous waste streams to a municipal wastewater treatment plant, or publicly owned treatment works (POTW), may be a cost effective disposal option. However, wastewaters that adversely affect the performance of biological wastewater treatment at the POTW will not be accepted. The objective of our research is to assess the effects of wastewaters that might be generated by new rare earth element (REE) beneficiation or recycling processes on biological wastewater treatment systems. We have been investigating the impact of yttrium and europium on the biological activity of activated sludge collected from an operating municipal wastewater treatment plant. We have also examined the effect of an organic complexant that is commonly used in REE extraction and separations; similar compounds may be a component of newly developed REE recycling processes. Our preliminary results indicate that in the presence of Eu, respiration rates for the activated sludge decrease relative to the no-Eu controls, at Eu concentrations ranging from <10 to 660 µM. Yttrium appears to inhibit respiration as well, although negative impacts have been observed only at the highest Y amendment level tested (660 µM). The organic complexant appears to have a negative impact on activated sludge activity as well, although results are variable. Ultimately the intent of this research is to help REE industries to develop environmentally friendly and economically sustainable beneficiation and recycling processes.

Jan 1, 2016

By E. Benguerel, G. Monteith, L. Centomo, S. Pelletier

In early 2007, it became apparent that with changing concentrate feeds, the magnesium (Mg) load projected for CEZinc starting in 2009 and beyond would quadruple and overwhelm the current Mg process bleed capacity. A project was started, following design for six sigma (DFSS) standards, to select both the optimal process and to evaluate its target capacity for the Mg bleed circuit. The economic and process risks of under or over-designing while Mg reduction efforts were underway at the mines also needed to be evaluated. This paper describes the project methodology, the impact on the plant, and some potential optimizations for CEZinc&apos;s basic zinc sulphate (BZS) Mg bleed process.

Jan 1, 2008

By O. Laitinen, M. Rudolph, J. A. Sirviö, H. Liimatainen, R. Hartmann, University of Oulu

The increasing complexity of the ores composition worldwide calls for suitable collectors with specific properties, such as selectivity, wettability, and in regard to current regulations, environmental sustainability. Therefore, collectors have to satisfy many features to improve the efficiency of flotation processes. Cellulose nanocrystals gain more and more interest due to the versatile synthesis routes which enable the integration of specific functional groups and components with different degrees of hydrophobicity within the molecular structure. Consequently, cellulose nanocrystals can be employed in flotation processes as depressant or collector molecules, respectively. Nonetheless, the usage of cellulose nanocrystals is still limited due to a lack of the characterization of nanocrystal-mineral interactions and the change of the surface wetting properties of minerals after adsorption phenomena between nanocrystals and minerals. In these studies, butyl-amine cellulose nanocrystal (BAC) and quartz are used as model system to investigate physicochemical properties of both, BAC and quartz, and examine the applicability of BAC in flotation processes. Therefore, the surface charge distribution and electrophoretic mobility of BAC and quartz are investigated and compared to understand the effect of electrostatic interactions between BACs, and BAC and quartz. Based on this, the adsorption of BAC on quartz is examined. Finally, microflotation experiments test the efficiency of BAC to be used in flotation processes. The flotation response is correlated to the specific surface charge of BAC revealing the dominant effect of surface charges on effective particle-bubble adhesions.

Jan 1, 2016

By Ting An Zhang, Chengzhi Jiang, Xiujing Zhai, Feng Xie

The extraction and concentration of nickel from aqueous solutions by emulsion liquid membranes (ELMs) using tributylphosphate (TBP) as extractant has been investigated in this research. The emulsion liquid membrane consists of a diluent (kerosene), a surfactant (Span 80), a mobile carrier (TBP), and a stripping solution (ammonia solutions). Important factors influencing the separation process including membrane composition, feed composition, and mixing speed have been examined. The results show that more than 90% of nickel in the feed solution could be extracted by ELMs under the experimental conditions, indicating the feasibility to use the designated ELMs to detoxify nickel-containing industrial waste solutions.

Jan 1, 2014

By William H. White

"AbstractThe value of anomalous metal contents of trees as an aid to the discovery of mineral deposits was tested under field conditions cm four known ore deposits. Results indicate that a base-metal deposit, or any deposit containing zinc or copper, casts a 'metal shadow' into the overlying soil which remains approximately positioned above the deposit, regardless of the type of overburden or the movement of groundwater.The unusually high content of zinc or copper in trees growing within the limits of this 'metal shadow' constitutes an anomaly which can be detected and ,plotted in the field The field kit and certain points of the field technique are described briefly; and the characteristics of plant anomalies and possible limitations of their use are mentioned.IntroductionRecent investigations concerning the metal content of trees indicate not only wide variations in the metal content of different species and in different parts of the same tree but, in addition, suggest that the metal content of a tree is related to that of the subjacent bed-rock. Abnormal values found by Warren, Delavault, and others in trees growing above or near orebodies suggest a new tool which may prove of considerable value in exploration work. Evaluation of this new tool must involve consideration of the following questions:(I) Is the technique one which can be used under field conditions by persons not specially trained; and can results be duplicated within reasonable limits of error? Rather than taking tree samples for subsequent laboratory analysis, it is highly desirable that analyses be made on the spot. This allows anomalous results to be checked and additional samples may be taken at key points."

Jan 1, 1950

By David Minson

On many occasions, operators have seen that high density and paste thickener performance does not meet the initial design expectations, and the installed equipment produces lower than expected thickener underflow solids content. This lower-density tailings slurry leads to more water and lower beaching angles being seen at the tailings storage facility (TSF). This not only reduces storage capacity, but also increases the risks of non-compliance with environmental permit constraints. Reasons for the shortfall in performance can be many, but perhaps the main problem is inadequate understanding of the critical components of thickener design and operation, with too much reliance placed on standardised design terminology; such as tph/m2. This paper discusses additional factors that influence high-density thickener operation and presents test work that defines “Dynamic Slurry Fluidity”, “Bed Compaction Rates”, and “Natural Slump Angles” for these high yield stress/viscosity slurries. Finally, the paper uses this data to define thickener geometry, drive torque, floor slope(s), rake blade configuration and how this can be used to provide engineers with more tools for in depth evaluation of a High-Density thickener design. INTRODUCTION Generally copper mines are high tonnage operations, with copper flotation concentrators producing high volumes of tailings slurries of milled solids and water. As a result, Tailings Storage Facilities (TSF) become very large and this, along with potential scarcity of water, favours a design that maximises storage space. In theory, the use of filtration equipment that achieves immediate water recovery, high TSF in-situ densities and high stacking angles are preferred for this duty. However, large tailings filter units are uncommon, and have high operating and capital costs that favour the use of thickeners. The use of high-density thickeners to produce a thick or near-paste like slurry with high un- sheared yield stress values above 100 Pascals, is becoming more common. The higher thickener underflow is required to not only maximise water recirculation within the mill, but to also increase beaching angles, maximise tailings storage capacity and minimise evaporation losses arising from large areas of superficial water. However, the reliability of this equipment is also under scrutiny and there is perhaps a need to better define these designs.

Jan 1, 2019

By Y. L. Mehta

The working experience of the Zinc Smelter, Debari, Udaipur with process modifications and iron control practices is described in detail in this paper. Most of the modifications were made at different times as part of capacity enhancement campaigns that led to distinct advantages, thereby increasing both zinc production and recoveries. This smelter came into existence in 1968 with a humble beginning of producing 18,000 metric tonnes (MT) of zinc per annum, using the conventional batch hydrometallurgical roast-leach-electrowinning technology. Zinc production capacity was increased stepwise to 45,000 MT, 49,000 MT and 59,000 MT, by making suitable process modifications and adopting new technologies, particularly in the leaching section. During these modifications, the process of iron separation as Moore cake was also changed to jarosite cake production. At present, jarosite is being disposed in a secured landfill at the Zinc Smelter, Debari (ZSD) and as Jarofix at the Chanderiya Lead Zinc Smelter (CLZS). As a result of subsequent in-house performance improvement and debottlenecking campaigns, this smelter could achieve further increases in production. Zinc production for the financial year 2005-06 was 81,000 MT.

Jan 1, 2006

By Jim Hazzard

A numerical investigation is presented to examine fluid flow in fractured rock slopes. In mining geomechanics, different numerical modelling approaches are used to estimate fluid pressures in open pit mines. The most common technique is the Equivalent Porous Medium (EPM) approach in which the fractured rock is assumed to behave as a porous continuum. Depending on the geometry and properties of the problem, this may not always be the best approach. The paper presents a parametric study to examine the effect of fracture spacing, fracture and matrix diffusivity and excavation rate on the fluid behaviour in rock slopes. Based on the model results, guidelines are provided as to when EPM models can be used and when different modelling approaches (e.g., discrete fracture flow) may be necessary.

Jun 1, 2012