Search Documents

By K. Shitogiden, Y. Samada, T. Miki

Steelmaking slag contains nutrition such as Si, P and Fe for acceleration of phytoplankton growth. Phytoplankton can fixate carbon dioxide more than any other species on earth. Hence, suppression of CO2 can be achieved by applying the potential of steelmaking slag as the nutrition for their propagation. When it is considered to supply nutrition from steelmaking slag to seawater, we must avoid dissolution of hazardous elements or change of pH of seawater by steelmaking slag addition into seawater. The protection against dissolution of fluorine into artificial seawater has been studied based on dissolution behavior of steelmaking slag and synthesized substances into artificial seawater in the present work. The dissolution mechanism of fluorine from steelmaking slag and buffering action of pH change are discussed by using stability diagram in seawater.

Jan 1, 2004

The Boleo project is located in Mexico close to the town of Santa Rosalia on the Baja Peninsula. The Boleo deposit contains copper, cobalt, zinc and manganese values as oxides with minor sulfides. The Boleo deposit is metallurgically challenging due to: 1) the requirement to recover four separate metals; 2) the presence of high levels of clay in the deposit resulting in difficult solid-liquid separations, and; 3) the need to use seawater for the bulk of the processing. Baja Mining, Bateman Engineering and SGS Lakefield Research have collaborated to develop and test a process flowsheet to recover copper, cobalt, zinc and manganese products at Boleo. The key steps in the flowsheet are: ? Feed preparation (scrubbing and ball milling of oversize) in copper raffinate ? Ore leaching using oxidative and reductive leaching ? CCD washing using high rate thickening technology ? Copper SXlEW ? Treatment of a bleed solution for cobalt, zinc and manganese recovery The process for cobalt, zinc and manganese recovery involves iron and aluminum removal followed by cobalt/zinc bulk extraction using CSIRO's DSX solvent extraction system and selective zinc and cobalt stripping. The zinc strip solution is evaporated to produce zinc sulfate monohydrate crystals to market and cobalt is recovered via a further SXlEW process as high purity metal. Manganese is precipitated as manganese carbonate from the DSX raffinate solution. This paper will review the Boleo process flowsheet and provide detailed results from the 2006 pilot plant operation conducted at SGS Lakefield in Canada.

Jan 1, 2007

By W. J. Witte, M. K. Witte

"INTRODUCTION A pilot heap leach project was conducted on the B. P. Selco Hope Brook ore located in southwestern Newfoundland. The pilot heap leach was undertaken to assess and confirm the following:1) To confirm that heap leach technology now currently used in the United States could be applicable to Canadian sites.2) To confirm gold recovery by the Heap Leach technology3) To assess and study potential heap leach environmental concerns in cold and wet climate.PROJECT LOCATIONThe Hope Brook Project is located near the southern coast of the island of Newfoundland, approximately 100 kilometers southeast from Stephenville, approximately 25 kilometers west of Burgeo, Newfoundland. Access to the property is limited to helicopter, float plane or by sea through Couteau Bay. The property was covered with muskeg and very few trees. Surface relief was moderate with many poorly drained boggy sections confined to small areas. Many small unnamed lakes were located on the property which provided water to small brooks and streams flowing to Couteau Bay.Several locations were reviewed for the installation of the pilot heap leach facility. Important parameters used to select a suitable location included sufficient land area, close proximity to but not on the ore body, reasonable protection from wind, sufficient supply of fresh water, close to a suitable location for a portable crushing plant, reasonable access to aggregate material for preparation of the test pad and ponds and suitable contours to minimize site preparation."

Jan 1, 1987

By P. Au, R. Kearsey, D. Y. Seo, Patnaik. P. C.

Three nickel based superalloys (7.5%Cr+5%Co+2%Mo+1%Ti+5%Al and Ni balance (wt%)) containing different amounts of W and Re were produced in the single crystal (SX) condition utilizing the Bridgman casting process. First, the effect of different levels of Re, and W on chemical microsegregation were investigated by EPMA quantitative analysis, and eutectic phase fraction analysis. Second, in order to investigate the effect of these refractory elements addition on oxidation behaviour, isothermal oxidation testing of the SX nickel based superalloys was conducted at 1000°C for 277 hours under 3 ppm moisture content of air in a thermogravimetric analyzer (TGA). All three SX nickel based superalloys revealed an excellent SX solidification structure with a common primary dendrite arm spacing of -250 µm and a large fraction of ?/?' eutectic located between the secondary dendrite arms. From the average EPMA compositional results, with the exception of Ni, elements such as Cr, Co, Re, Mo, and W all tended to segregate towards the dendrite core during solidification, while Al, Ti, and Ta were present in greater quantity in the last liquid phase to solidify, which resulted in large eutectic ?/? ' phases to form within the interdendritic regions. As the nominal level of Re increased, microsegreagation of Re, W, Cr and Mo increased, indicating that Re had a much greater influence on partitioning behavior compared to W. Figure la shows the specific mass gain as a function of exposure time for each alloy. An alloy with 2wt% of W and Re (Alloy B) exhibited less weight gain compared to two other alloys with either higher content of W or Re (Alloy A and C). Microstructural and compositional analyses of oxidized samples were conducted using SEM and EDS. Figure lb shows the typical surface morphologies of the oxidized Alloys A and B. It is evident that more oxide nodules (indicated by arrows in the figure) were presented in Alloy A. It is speculated that the amount of these nodules was responsible for more mass gain in Alloy A compared to the two other alloys. From the examination of the longitudinal section of the oxidized samples as shown in Figure 2, for Alloy A, nodules actually penetrated deep into the material. For Alloy B, however, a relatively uniform and continuous oxide layer was developed and deeply attacked areas were not observed. It was also found that preferential oxidized regions were located at the area between the ?/?' eutectic phase and the dendrite arms where the concentration of refractory elements was relatively high. Therefore, it is plausible that the oxidation kinetics of these alloys is related to the extent of microsegregation.

Jan 1, 2004

By P. Mattar

The geotechnical importance of studying fluid flow through porous media and soils in particular, becomes evident when dealing with groundwater movement in surficial geomaterials that can be initiated by hydraulic gradients that develop during construction activity, groundwater extraction, impounding of reservoirs and groundwater recharge during adverse climatic events. In a geotechnical context, rocks are regarded as virtually impermeable materials, with comparatively greater resistance to flow of water through their pore structure. The importance of the permeability of rocks comes to the forefront when deep geologic formations are used in geoenvironmental activities for disposal of hazardous and toxic materials. The permeability of the rocks encountered is of critical importance to these geoenvironmental activities since the movement or transport of the hazardous materials during their eventual release will be largely governed by the permeability characteristics of the geologic formation. The estimation of the permeability characteristic of geologic formations is a non-trivial exercise since the measure of permeability can be influenced by the scale at which the measurement is made. Regional-scale and borehole-scale estimates of the permeability can be greatly influenced by the inhomogeneities, including fractures, fissures, solution channels and other anomalies that are present in naturally occurring geologic media. These anomalies are considered to be site specific and can only be determined in a reliable fashion by either conducting tests at the appropriate scale or in the regional-scale through inverse analysis of tracer movement patterns in rock masses. The estimation of the permeability of intact units of a geologic medium has important geoenvironmental applications in connection with storage of wastes since the units in which repositories will be located should be sparsely fractured and the sealing of the fractures and fissures are a prerequisite to developing an efficient solution for storage. The intact permeability of geomaterials is therefore regarded as an important property that influences efficiency and reliability of geoenvironmental solutions for deep geologic disposal. The permeability of geomaterials such as concrete and cementitious grouts are also important to many geoenvironmental and infrastructure applications where durability of structural materials in general and cements used for sealing deep boreholes and other access shafts employed in waste management endeavours is influenced by the permeability characteristics of these materials

May 1, 2009

By Aimee Williamson

Bio-mining is a cost-effective, energy efficient and potentially environmentally protective method of exploiting a variety of ore deposits, from high-grade base metal deposits of nickel to lower-grade uranium deposits such as are found in the uraniferous quartz-pebble conglomerate beds of the Quirke Syncline, Elliot Lake, Ontario, using bacterial metabolic processes are used to enhance the solubilization of the metal(s) of interest. The cost effectiveness of bio-mining in Elliot Lake depends on the bacterially-influenced dissolution metals of economic importance, as well as on the ability to suppress microbiological activity following the release to solution of the economically important elements. This poster provides an overview of elemental recovery results and release kinetics for more than 50 elements. The data is obtained using a combination of advanced spectroscopic tools (ICPAES and ICP-MS) to analyze solutions obtained from a series of environmentally controlled biologically mediated uranium ore extraction experiments. The focus will be on rare earth elements, potential environmentally toxic elements, and metals of economic importance. Furthermore, the importance of these findings will be put into an economic and geologic context for the re-development of the mining industry of the Elliot Lake Camp.

Aug 1, 2010

By A. L. Williamson

Bio-mining, the use of micro-organisms to recover elements of interest, is potentially useful for the economic extraction and recovery of ore metals from a variety of ore deposits, including the lowergrade uranium deposits found in the uraniferous quartz-pebble conglomerate beds of the Quirke Syncline, Elliot Lake, Ontario. The metabolism of chemolithotropic bacterium Acidithiobacillus ferrooxidans depends on an ability to derive energy and reducing power from the oxidation of ferrous iron found in a varirty of iron sulphide minerals associated with base, precious metal and uraniferous ores. The characteristics of this bacterium, especially the ability to oxidize both iron and sulphur with an associated high tolerance of low acidity, allow the organism to contribute significantly to bio-mining processes. Under ideal conditions, A. ferrooxidans promotes the oxidation of ferrous iron in low sulphide ore materials, breaking the crystal structure of the ore minerals .releasing protons to the surrounding solutions, thus promoting the dissolution of uranium and rare earth elements, among others. This paper provides an overview of elemental dissolution and release of uranium, rare earth elements and investigates the acid generating potential of the final residues, from a series of environmentally controlled, biologically-mediated uranium ore extraction experiments. The findings will be used to guide in the design of larger scale bio-leaching experiments to further assess the potential for successful bio-mining operations along the Quirke Syncline.

Aug 1, 2010

By Edgar L. Horner

"The objectives of the Wabush Mines tailings stabilization program are to control dust Ii/t-off and to rehabilitate the disposal area. The evolution of the program started with test plots in 1970, these being continued and expanded upon through 1974. In 1976, a 35-acre vegetation field trial was attempted and failed, part of the failure being attributed to lack of adequate equipment. Subsequently, equipment was purchased and during the summer of 1979-80 extensive areas were treated. The program was also expanded to include the evaluation of chemical and water spray stabilization versus vegetation in areas where shorter-term control is required. In addition, during the summers of 1979-80, spruce bog material was spread over about 100 acres and seeded.The approach to reclamation by vegetation at Wabush is one of soil building. Work to this point indicates that iron ore tailings can be converted to a soil capable of supporting plants. Plans for the Wabush tailings disposal area should make dust lift-off from inactive tailings areas negligible within the next few years."

Jan 1, 1981

By Karim Ramji

The extractive sector today faces growing social, legal and political risks (SLPs) from so many different stakeholders including national and local governments, name and shame groups, civil society and environmental groups, and the ?Occupy? movement. Beyond these stakeholders, there are the indigenous peoples who have growing legal, social, political and economic influence which can often determine the outcome of the Project. The development curve in the extractive sector from initial exploration to mine start-up has become longer, steeper and more risky and expensive as these SLPs have grown in scope and complexity. Even if a project is permitted or starts commercial production, its ongoing development and operations are also facing these SLPs. The continuous assessment of these SLPs and the strategy to mitigate for them has now become critical for every project in the extractive sector. A project will only be successful if it is able to obtain the legal permits to operate, then withstand any judicial reviews, and then also to be able to gain and maintain the Social License to Operate (SLO). Stakeholder identification, management and engagement are key risk-mitigation tools. This paper focuses on the growing influence that indigenous peoples are now enjoying and the impacts on the extractive sector. Indigenous peoples are a unique stakeholder group because their legal rights and interests to lands and resources, their aboriginal title and rights, are gaining more recognition. When indigenous peoples form alliances with other stakeholders, this simply adds to their growing momentum and leverage, and this can become a daunting challenge for the extractive sector. More due diligence is required by companies to understand and assess the challenges posed by operating in areas claimed by indigenous peoples. There is a real need for mining companies to develop an effective indigenous engagement strategy to address these challenges in order to successfully convert risks into opportunities. Early identification and engagement with the indigenous peoples is required and the goal should be to conclude an Impact Benefits Agreement (IBA) with the affected indigenous peoples. The real objective must be to develop a real and transparent relationship between the company and the indigenous peoples so as to gain and maintain the SLO.

Aug 1, 2013

By Peter N. Calder

Long range mine planning involves developing a mining sequence that schedules the extraction of the ore and waste materials within a final pit limit. The objective is to define a sequence that best meets the defined strategic objectives. The main steps in the creation of an open pit mine plan are the final pit limit design, the design and sequencing of the mining phases, equipment selection and operating cost estimation. Flexibility is the key strategic element in developing a mine plan. Planning the extraction sequences and rates for the various mining areas is a challenging and demanding activity. It is often necessary to consider numerous alternative strategies and what if scenarios. The number of alternatives that can be studied with limited manpower and time resources is restricted. In order to investigate strategic aspects of mine planning, a system to generate workable mine plans rapidly is required. The concept of Visual Mine Planning is that the engineer can visualize the current plan, easily change a component of the plan, such as the annual cut-off grade schedule or the production rate within a particular Phase, and immediately see the effect on the mineralogical and cash flows. If the desired result is not achieved, a change is made and the effect is again immediately seen. This paper presents results of research in this area conducted at the Pontificia Universidad Católica de Chile. The work includes the examination of cut-off grade strategy, sequencing, blending, stockpiling and shovel-truck fleet requirements using simulation.

May 1, 2003

By J. Elbrond

"This paper describes qualitatively the progressive are losses and rock dilution in a mining project from the geological modelling to and including the concentration. A simple theoretical model of the net present value of a deposit, assuming a log-normal grade frequency function, is used to find the pair of decisions on rate of production and cut-off grade, which maximizes the net present value. Various degrees of ore losses and rock dilution are then applied on this optimum, and the resulting decreasing net present values are calculated, as well as the increasing cost of metal and the increasing metal losses as a function of are losses and rock dilution.IntroductionDue to a variety of uncertainties, to inevitable lack of precision in deposit estimation and in mine planning, and due to production constraints, ore losses and rock dilution occur throughout the many phases of a mining project. The phases range from the geological definition of the orebody, over the cut-off grade optimization and decision, over the design of the mining method and the actual mining to the ore dressing, where the final loss of valuable ore into the tailings occurs. Quantification of ore losses and rock dilution are mostly difficult if not simply impossible to obtain. At the end-phase an estimate of the total dilution may be obtained with some degree of precision by observations of the amounts and analysis of concentrate and tailings. It is much more difficult to estimate the total ore losses because the uncertainty of the geological modelling in the initial phase and in the mining phase is very difficult to quantify, despite the use of geostatistics for grade estimation.Many attempts at quantification of ore losses and rock dilution have been made and some examples are shown in Table I. Although they differ widely from each other, it is obvious from these figures that ore losses and rock dilution are significant and have considerable effects on the economical results of a mining operation. Life length, net present value, cost of producing metal and the loss of metal are all affected."

Jan 1, 1994

By S. K. Sadrnezhaad, B. Hashemi, Z. A. Nemati, Z. Moghimi

Based on the kinetics relationships of a solid - gas model, a software was developed for the prediction of oxidation. Preliminary prediction of oxidation by the software and experimental results of MgO-C refractories were studied and compared. By using the obtained data from this approach, the effective diffusion coefficient, intermolecular diffusion coefficient and diffusion activation energy in the MgO-C refractories, containing various amount of graphite were obtained at different temperatures. First of all, the prediction by the software was very compatible with experimental results, for different oxidation mechanisms in the MgO-C refractories. The results showed that pore diffusion is the predominant oxidation mechanism in this system. The results indicated that when graphite content was above 10wt%, the intermolecular diffusion coefficient was independent from graphite content, and it was closed to a constant value at each temperature.

Jan 1, 2004

By M. Reza Bateni, M. Zandrahimi, J. A. Szpunar

Titanium aluminides and nickel aluminides offer the potentials, as coating materials, for high temperature and aerospace applications. In this research, attempt has been made to develop Al-Ti and Ni-Al intermetallic compound coatings on the surface of Inconel 738. The coatings applied through pack cementation and simultaneous diffusion annealing processes. Scanning-electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDAX) and grazing angle X-ray diffraction were used for evaluating of coating structure. It was demonstrated that the pack cementation technique could be used to develop TiAl3 and AlNi intermetallic compounds coating on Inconel 738 substrate. When pack cementation technique is based on a halide-activated pack with aluminum and titanium powders, the coating consists of TiAl3 intermetallic compound phase. Whereas, by pack aluminization of Inconel 738, the coating consists of AlNi intermetallic compound phase.

Jan 1, 2004

By George Dogbe

Open pit optimization forms the basis of mine design, production planning and construction of mine facilities. The negative effects of this phase may include substantial reductions in ore recoveries, relocation of waste dumps and surface infrastructure, extraction of unwanted waste, with a cumulative effect on mine value reductions. As a result, this area has received significant research focus using linear and dynamic programming, heuristic, genetic and stimulation algorithms and the graph theory. These algorithms are derived from rigorous mathematical models, but they are built on the assumption that all the periodic production capacities are extracted at the time of analysis. This assumption weakens the models because mining occurs over significant time period. In order to develop a comprehensive model that accounts for the timing of material extraction, the current models, which are built on the economic block value (EBV) concept, must be modified to account for time. In this paper, the authors develop a model of the optimization problem using the 2-D Lerchs-Grossmann?s optimization algorithm. This model is used to investigate the effect of periodic discounting on the optimal pit layout design by designing an integrated pit optimiser (IPO) that incorporates ?production scheduling?. IPO uses the ensuing discounted economic block value (DEBV) as a basis for the pit optimisation process. The time-dependent model is compared with a time-independent model. The results show that discounting has no effect on the optimal pit contour although the reported pit value is overstated if the EBVs are used instead of the DEBV. The authors, however, believe that this conclusion may not be general and could have been influenced by the nature of ore body geometry and the proposed mining strategy.

May 1, 2004

RISKGATE is an interactive online risk management system developed by the Minerals Industry Safety and Health Centre (MISHC; University of Queensland) to assist the mining industry in implementing continual improvement in management of major unwanted events, and so maximising health and safety performance. A comprehensive body of knowledge has been compiled from diverse mining industry experts for risk management of tyres, collisions, fires, isolation, strata underground, ground control open cut, explosions, explosives, manual tasks and slips/trips/falls. This paper presents an overview of the body of knowledge captured from diverse mining industry experts for the management of unwanted strata incidents, and explosions in the underground environment. This knowledge is divided into a series of initiating events within both topics (as listed) with further degrees of classification based on design, operation, and management concerns. Strata Underground Initiating Events: Explosions Initiating Events Loss of strata control at longwall face Fire or ignition in a sealed area Loss of strata control in outbye roadways Fire or ignition in an unsealed goaf area Loss of strata control in roadways under development Fire or ignition in an extraction face Loss of control of overburden and caving behavior Fire or ignition in outbye Loss of pillar system stability Loss of control of goaf edge in pillar extraction Fire or ignition in a development panel or first working Loss of strata control in shafts The system guides the user in generating substantive and leading edge controls to assist industry stakeholders in the design, management and reporting of organisational and regulatory compliance requirements. From a broader industry perspective, RISKGATE provides an environment for knowledge capture and knowledge exchange to drive innovation and best practice in the identification, assessment and management of risk. By capturing operational knowledge from industry experts, RISKGATE provides a cumulative corporate memory at a time of high personnel turnover in the coal industry.

Aug 1, 2013

By J. Mosher, G. Banini, J. Hollow, A. Villanueva

Prior to installation of High Pressure Grinding Rolls (HPGR) at PT Freeport Indonesia (PT-FI) a series of laboratory tests were carried out to determine the design parameters and also determine key performance indicators (KPIs) for the industrial unit. The design parameters derived from the lab test work were then scaled up to estimate the industrial capacity of the HPGRs to be installed. These parameters include specific power draw, specific throughput, and specific force, rolls speed, product size distribution and wear rate of the rolls. This paper compares the performance of the scale-up procedure against the installed industrial size HPGR. Overall, the specific throughput of the industrial size HPGR is higher by a minimum of 30% compared to the expected scale-up value. As a result of the high specific throughput, the specific power draw and grind sizes are below the scale-up expectations in the commercial application. The impact of these factors also contribute to a lower than expected wear rate on the industrial rolls. Installed rolls achieved a service life in excess of 18,500 hours relative to the target of 6,850 hours predicted from the laboratory testing.

Jan 1, 2012

By Chris D. Veldhoen

If you ask most diamond drillers if they have ever encountered methane gas, the answer would probably be yes. This paper explores a serious methane gas explosion that the author experienced while diamond drilling at a northerly Ontario mine. It is hoped that by documenting this event, people may be alerted to the hidden danger posed by confined methane in underground workings. Methane gas tends to be a problem the deeper you get in any Canadian gold mine. Common procedure when encountering methane is to take readings at the collar of the hole and at different lengths from the source. Monitoring continues until the readings drop below 0.25 ppm. Methane is a tasteless odorless gas that is usually locked up in the seams of the rock or is a product of decaying organic material. Occasionally, the gas is released abruptly over a short period of time. Sometimes the gas can continue to vent for months or even years. In small concentrations, methane is relatively safe. In concentrations under 0.25 ppm methane gas is considered safe to work around. Concentrations over 0.25 ppm can become dangerous. During the summer of 2001, Chris Veldhoen was drilling at a gold mine in Ontario. There were three electric hydraulic diamond drills on the 39 meter level, approximately 5200 feet deep. Two Longyear LM 55 drills were about 40 feet apart and another LM 75 was about 2000 feet away. The two LM 55?s were set up to drill holes no deeper than 350 meters. All three drills had been set up on the same spot for more than a month. None of the three drills had ever encountered methane gas in the entire time they had been drilling on the level. On the day shift of July 13 2001, the driller on Chris? cross shift hit a small pocket of gas. He tested the hole and got a reading above 0.25 ppm. He proceeded to rope off the area with a ?DO NOT ENTER - METHANE GAS? sign and a rope denying access beyond the sign. On Saturday, July 14, Chris was instructed to install a Margo plug in the hole that was emitting methane gas. Methane is usually odorless, but occasionally when encountered underground, is accompanied by a rotten egg smell. As he walked to the drill, he could not smell methane gas. He proceeded to test the hole and got a reading of 0.22 ppm methane. This number was in the acceptable range for drilling, but he plugged the hole anyway.

May 1, 2004

By T. Maruyama

Tamano Refinery started its operation in 1972 with the cathode production capacity of 84,000 tons per year. After several expansions, the production capacity increased to 228,000 tons per year in 2001. In this paper, we are introducing our next expansion projects starting October 2006. The project expands the production capacity of cathode from 228,000 tons to 260,000 tons per year. The main modification of this project is the conversion to the ISA process and the installation of additional seventy-two cells in the No.2 Tankhouse. The No.1 Tankhouse remains the same, using the conventional process. Half of our starting sheet cells are converted to commercial cells. The other expansions are to enlarge our purification plant. And the incidental facilities are enlarged, for example, circulation tanks, heat exchangers, filtration system, etc. Finally, this paper describes those improvements to our refinery performance and preparing for future expansions.

Jan 1, 2007

By J. Schmidt

Cold drawing of copper wire rod is usually combined with an in-line annealing process to adjust the ductile microstructure of the wire again. One important key factor for successful annealing is the quality of the copper itself. Rod producers can check the recrystallization behaviour of the rod by different methods: chemical analysis, Spiral Elongation Test (SEN) as well as the Rapid Elongation Test (AR) are some examples of common testing methods. The comparison of the results of these methods does not always show sufficient correlations. The paper introduces firstly the SEN and AR-Tests and their different approaches to the mentioned task. The second step is to compare some results of the SEN-Test with the results of the AR-Test and identify causes of deviations. Thirdly, the effect of pre-annealing is discussed, which is especially common for wire rod with diameters of more than 8 mm.

Jan 1, 2007

By M. Huang

Electrodeless conductivity was employed to investigate the feasibility of continuous on-line monitoring of the free acidity of sulphate and/or chloride solutions of Cu and other base metals from various hydrometallurgical processes. These solutions were measured with both commercial and experimental electrodeless conductivity sensors from 15 to 250°C. It was confirmed that hydrogen ion has the greatest impact on conductivity by carrying the bulk of the current because it is the most mobile ion. In combination with a solution speciation analysis the conductivity sensor can be calibrated to account for the contribution of Cu electrolytes as well other dissolved salts allowing fast and accurate on-line measurement of free acid. The sensor was tested at both lab and pilot scale with very good performance. The average difference between the measured and the titrated acid concentration was less than 5%, which is excellent for industrial applications.

Jan 1, 2007