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By Ing. H. Kellerwessel, Ing. M. Esna-Ashari

This paper refers to the new crushing and grinding process, invented by Professor Schonert (Ref. 1), Clausthal, Germany. The process is known as high pressure particle bed comminution or interparticle crushing. Several papers already describe fundamentals of the process, the equipment used, results of lab size and large scale tests and the first results of commercial operations (Ref. 2 to 7). Of course, we will treat the topic from the perspective of a downstream gold ore upgrading or leaching process. Some recently executed testwork indicates that the process provides special advantages in this field. To describe the process generally, in view of the already existing publications.

Jan 1, 1998

By Tim Gitzel

Thank you for your introduction, and thank you to the CIM for inviting me to make a presentation to you today. This is my first opportunity to report to you on the status of the Canadian uranium industry and I am pleased to tell you that the industry is in good shape, and well positioned for the future. As you will no doubt be aware, Saskatchewan benefits from the world?s largest known highgrade deposits of uranium as well as from a high level of provincial, public and northern community support. It is within this unique combination of geology and community that our industry operates. Uranium markets have been extremely competitive for a number of years for several reasons. First, deregulation in the nuclear electric power industry has tended to encourage fuel buyers to use up their large inventories built up at a time when rapidly increasing demand was anticipated. Second, alternate sources from surplus commercial stocks, military materials and reprocessed fuel have presented a major additional source of uranium supply. Today, these secondary supplies are meeting about half of uranium reactor feed requirements. Canada (that is, Saskatchewan) is the world?s largest ?natural? uranium producer with about a third of the global production. Saskatchewan?s mines produced more than 30 million pounds of yellowcake in 2002. Despite low prices, steady demand for uranium will continue. In fact, an increase in world uranium production in 2002 helped feed a more than 3 per cent increase in reactor fuel demand. Low cost production is important for surviving low market prices, but investments are based on longer-term strategies rather than simply responding to market cycles. Cost is not the only issue. In these times of increasing regulatory and public scrutiny we must continue to earn the trust of our stakeholders by adopting the highest standards and staying on the leading edge of technical, social and environmental developments. Managing these issues is as important as traditional concerns of ore grade and cost of production. The last two decades of the 20th century saw the Province of Saskatchewan rise to prominence as the leader in uranium production from facilities, which were at the time deemed world class. These facilities are now either at - or nearing - the end of their production years. We are now bringing on new facilities that will position Saskatchewan to remain the world leader in uranium production for many years to come.

May 1, 2003

By Hudson S. B

With a particular electrode configuration, and a particular combination of electrode voltage and roll speed, a relatively small increase in electrode voltage, or a relatively small decrease in roll speed, resultsin a marked improvement in the separation of zircon from ilmenite. In general, fine minerals can be separated using a higher roll speed, or a lower electrode voltage, than is required to separate coarse minerals. The ionizing electrode should be reasonably close to the point at which mineral is fed on to the roll, and nearer to the roll than the non-ionizing electrode. The optimum conditions for the separation of zircon from ilmenite may not apply for the separation of other non-conductors from other conductors.INTRODUCTIONAlthough the high tension separators used in the Australian beach sand industry are efficient, this efficiency has been gained very largely by a process of trial and error, and not by a systematic study of the effects of changes in the operating variables. The optimum roll speed for a particular electrode position and electrode voltage, and the optimum electrode voltage for a particular roll speed and electrode position, can both be determined quite readily. It is not so simple to determine the optimum electrode position for a particular electrode voltage and roll speed. The reason for this is that the electrode used in high tension separators consists of two parts-an ionizing and a non-ionizing electrode respectively. The angular and radial positions of these electrodes, relative to the feed roll and to each other, affect the behaviour of conductors and non-conductors to varying degrees.

Jan 1, 1962

By Cleusa Cristina Bueno Martha de Souza

Hydrometallurgical techniques for processing metals are becoming an efficient method for recovering metals. Although batteries' manufacturers have got rid of mercury content, some efforts have been made for recovering other metals enclosed in the battery formula. This paper discusses the bench scale experiments in the purification process of leached solutions from alkaline spent batteries. After leaching process using sulfuric acid as leachant, the solutions containing Fe, Cd, Pb, MIl, Zn and K were neutralized to precipitate iron hydroxide. In a second step, the purification experiments were carried out with excess of zinc dust to try to remove Cd while Mn and Zn still remain in the solution to be recovered in an electrolysis stage. The purification experiments procedures were conducted at different temperatures and times to find out properly conditions from the viewpoint of metals removal After filtration the solutions were submitted to chemical analysis to certify the metals content extracted.

Jan 1, 2001

By R. Sellaro, E. Sarver

It has long been understood that extended occupational exposures to respirable mine dusts can lead to chronic lung disease. In underground coal mines, coal workers pneumoconiosis (CWP) and silicosis are major concerns. While many efforts have been made with the aim of understanding the mass-based concentrations and silica contents of respirable dusts under a variety of mining conditions, little research has been completed in characterizing dust at the individual particle level (by composition, size and shape). This study employed scanning electron microscopy with energy dispersive x-ray (SEM-EDX) to analyze dust samples collected from an underground coal mine in Central Appalachia. The results indicated that particle characteristics can vary widely between locations, though many trends might be explained based on knowledge of mining conditions. A continuous personal dust monitor (CPDM) was also used during the collection of some samples to determine respirable dust concentrations, which were compared against estimated concentrations based on the particle-level analysis.

Jan 1, 2014

By Sharpin P. C

The countercurrent gas-solid heat transfer during the drying of brown coal briquettes in the pilot carbonization plant at Morwell has been analysed and theoretical gas and solid temperature distributions through the drier have been calculated. Although the calculations rest on several simplifying assumptions, the theoretical temperature distributions compare well with those observed in practical operation. Valuable conclusions are reached as to the effects of changes in drier operating conditions on the rate of drying of the briquettes which controls the strength of the char produced. The analysis shows why a limitation was reached in the improvement of char strength in the pilot plant in 1961 due to the performance of the drier and a prediction is made of a way in which the limitation could be overcome.

Jan 1, 1966

By E. H. Henderson

MR. R. V. NEILY stated that he had at one time operated at Goldenville. The practice and results are much the same now as in the olden days. Inside plates were then found to be a source of trouble and had been removed. At the Libbey mine, Queen's county, the sulphides carried considerable gold, and $45.00 to $60.00 per ton had been recovered from the concentrates by roasting and chlorinating. Later, concentrates were treated with bromocyanide. Following that practice, a cyanide leaching plant was installed, which did not require concentration of the tailings. Cyanidation brought a recovery of around 95 per cent, with but $300 worth of plant. In Nova Scotia, the ore of each locality presents an individual problem of its own as to treatment required. Ma. W. B. Timm stated that, in the majority of Nova Scotia gold ores, more than 75 per cent of the gold content is free-milling and, naturally, stamps are most efficient for collecting and amalgamating this gold. In Ontario and the West, they had got away from stamps, and perhaps the main reason was that the supply of battery-men, who came from Nova Scotia, had died off. Ball-mills had been installed, which required smaller space and handled large tonnage, even though, as far as amalgamation goes, the stamps were probably more efficient. If concentration is to be done, ore from stamps is usually in better shape for recovery in passing over the tables, as there is no slime. With the ball-mill, flotation is necessary. The better practice, undoubtedly, is to take out what gold is possible before it is all smashed up, as in the ball-mill, though recent developments in the ball-mill make it possible to trap and take coarse gold directly from the mill. In this way, cyanidation is speeded-up, due to saving of the time the coarse gold would take before going into solution. PROFESSOR A. E. FLYNN found it unusual in these days to read anything in favour of the stamp mill, and thanked Mr. Henderson for the excellent paper in which he upholds the stamps and backs his opinion with facts from actual operations. For the typical Nova Scotia ore, containing coarse gold, stamps are un¬excelled. It used to be said that the virtue of stamps is that they brighten the gold for amalgamation. Although this saying is almost classical, it is not true, for gold is never brighter than in the native, untouched state. Any hammering that gold gets makes it more difficult to amalgamate.

Jan 1, 1935

By Xiang Ma, Halvor Dalaker, Kai Tang, Stefan Andersson

Silicon carbide (SiC) is one of the most important non-oxide ceramic materials for many industrial applications and is mainly synthesized by carbothermic reduction of silicon oxide by coke above 2200°C. Replacing natural gas (mostly methane, CH4) for coke in SiC synthesis could considerably reduce energy consumption and CO2-emissions owing to higher carbon activity of CH4 at lower temperature. The generally accepted reaction mechanism is that SiC is synthesized through gaseous intermediate silicon monoxide, SiO. In the present study, the reaction mechanism for the SiO and CH4 gaseous mixture has been examined using atomic scale modelling. Molecular dynamics (MD) using a reactive force field (ReaxFF) has been utilized to examine the initial stages of reactions involving a gas mixture of SiO and CH4 and surfaces of SiC. The MD results revealed some interesting SiC formation mechanisms. The reaction energies of the critical intermediate species were also estimated by density functional theory (DFT) calculations and the implications for the force field parameters used in ReaxFF was discussed.

Jan 1, 2015

By C. A. WARNER

AN OIL and gas mining lease contract, as entered A into by and between 'the lessor and the lessee, contains certain express covenants stipulating, in part at least, the exact performance thereof; it also contains certain implied covenants, among which may be included that of protection of the leased premises against drainage by the drilling of necessary offset wells. In the drilling for, and production of, oil and gas, however, it not infrequently happens that the lessee, acting in good faith, does not deem it prudent to, drill a test thereon even though the location for such test is offset by a producing well on an adjoining lease. Such conclusion, on the part of the lessee, is generally construed by the lessor as constituting a breach of the implied covenant mentioned above, and he may take proper action to secure satisfaction therefor. The action against the lessee is generally for cancellation or relinquishment of the lease, together with, or apart from, claims for damages allegedly sustained through failure to properly protect against drainage of the leased premises.

Jan 1, 1931

By E. H. W. Hornbrook, P. W. B. Friske

Paper presented at the 28th International Geological Congress, Washington DC, July 1989 (International geochemical mapping sessions). The objective of the programme is to establish and maintain a nationally consistent geochemical drainage database. Towards this end systematic surveys have been conducted since 1973. To date more than 200 surveys have been completed to the required standards, representing 180 000 sites and covering about 2 100 000 km2 throughout Canada

Jun 13, 1905

By Richard C. Corson

The objective of blending materials in a bedding pile is to reduce the variation in successive samples taken from the materials to be blended. In designing a bedding and reclaiming operation, several mechanisms are available to effect the reduction of variability, or increase in homogeneity, of the materials. These mechanisms can act before stacking, in the stacking process, in reclaiming and after reclaiming. In evaluating alternative methods of stacking and reclaiming, the potential user must judge each method on the basis of certain criteria; the capital cost of the equipment, the allowable absolute variability of the reclaimed product and the effectiveness of blending. Several stacking and reclaiming methods have been tested using a computer simulation. Based on the results of this program, factors were developed to describe the effectiveness of blending for chevron stacking of discrete materials and preblended materials, bucket wheel reclaiming and drum reclaiming. From these factors, the total effectiveness of a combined stacking and reclaiming system can be determined.

Jan 1, 1985

By John C. Machisak

THE INJURY data and experience at quarries and related plants of the United States are presented in this publication under the following general sections: (A) General injury experience: Tables 1 through 3: Contain current data on the number of injuries, injury-frequency rates, location, accident agency, degree of injury, and related employment data. (B) Injury experience at different kinds of quarries: Tables 4 and 5: Contain current, data on number of injuries, injury-frequency rates, locution, accident agency, degree of injury, and related employment data. (C) Injury experience by States: Tables 6 through 19: Contain current data on the number of injuries, injury-frequency rates, accident agency, degree of injury, and related employment data.

Jan 1, 1958

By Ailton S. Ferreira, Rubén J. Sanchez Rodriguez, Sergio N. Monteiro, Felipe Perissé D. Lopes, Teresa E. Castillo

"Polyester composites reinforced with natural lignocellulosic fibers have, in recent times, been gaining attention in engineering areas as lighter and cheaper alternatives for traditional composites such as the ""fiberglass"". One of the strongest, the curaua fiber, is today being considered as reinforcement of composites for automobile interior parts. In fact, several research works are currently being dedicated to curaua fiber composites since physical and mechanical properties are required for practical uses. In this work, the thermal behavior of polyester composites reinforced with up to 30 % in volume of curaua fibers was investigated by differential scanning calorimetry, DSC. The results showed endothermic and exothermic events associated with water release and possible molecular chain amorphous transformation. Comparison with similar composites permitted to propose mechanism that explains this DSC thermal behavior.IntroductionThe modem composite materials, especially those reinforced with synthetic fibers such as glass and carbon, have been used since last century to attend the demands required by most technological fields, from home appliances to aerospace [1]. In fact, fiber composites offer significant advantages over monolitic materials, such as common metallic alloys, plastic and ceramics. One of the most important is the ratio between the ultimate stress and the density, known as the specific strength. For example, in common glass fiber polymer composites, the so called ""fiberglass'', the specific strength of around 400 MPa.cm3/g is higher than any conventional monolitic material. However, drawbacks exist. The energy required to fabricate ""fiberglass"" generates large emissions of C02, which are responsible for global warming. Moreover, ""fiberglass"" is not recyclable and cannot be incinerated [2]. As a result, most synthetic fiber composites end up in landfills or contribute to rivers and oceans pollution."

Jan 1, 2011

By Juan Sodi, John F. Elliott

The standard free energy of ReS2 has been measured in the range of 1050° to 1250°K using H2/H2S mixtures and a slight variation of the method described by Hager and Elliott.1 The result is: The experimental method and apparatus were modified slightly for this study. Measurements on Cu2S were made to verify the application of the method to the work on ReS2. THE EXPERIMENTS AND RESULTS Briefly, the experimental method consisted of exposing a chip of copper or rhenium at a known temperature for 8 hr to a slowly flowing gas stream at the same temperature in which Ph2S and PH2 were known. The chip was withdrawn quickly from the hot furnace, and subsequently it was inspected for the presence of a sulfided surface. In the experiments described here, there was no ambiguity in any case as to the presence or the absence of the sulfide. At a given temperature, gas compositions for sulfidization were explored systematically until two compositions were found whose values of ?G°, Eqs. [I] and [2], were within approximately 100 cal of each other, one of which was sulfi-dizing and the other was not. These are termed the "straddle" compositions and it is assumed that the equilibrium composition lies between them. The chief modification to the apparatus, which is shown schematically in Fig. 1 of Ref. 1, was to support the metal specimen on a small alumina boat which could be moved along the reaction tube, 6 mm ID, by platinum wires. An appropriate seal at each end of the reaction tube permitted the sample to be moved from the cold end of the tube into the hot zone in 2 to 3 sec, and the sample could be withdrawn equally rapidly. Thus, it was possible essentially to quench the specimen from the reaction temperature with the reaction gas or helium flowing and without danger of breaking the reaction tube. The usual practice at the end of the experiment was to switch the gas system to the helium tank, flood the reaction chamber with helium, and pull the sample out of the hot zone. The purpose of the modification was to permit study of the sulfidization of copper without the complication of the back-reaction between the gas and the specimen as the latter cooled during slow withdrawal of it from the hot zone; this was a problem in the earlier work.&apos; A further improvement located the tip of the temperature-indieating thermocouple and the specimen precisely at the hottest part of the furnace. A carefully calibrated thermocouple, with its tip at the position of the specimen and with other conditions duplicating those of an actual experiment, showed that in the temperature range of 900° to 1122°C the temperature of the specimen differed from that of the tip of the indicating thermocouple by less than 0.5°C. The two positions were 0.5 cm apart. The reaction gas was prepared from ultrahigh-purity hydrogen (<l ppm O2, <0.5 ppm H2O) and CP grade hydrogen sulfide (99.5 pct H2S). High-purity helium (99.995 pct He) was used. All of these gases were purchased from the Matheson Co. All flow meters were recalibrated by the soap-bubble method with hydrogen, H2S, helium, and several gas compositions used during the study. These calibrations gave a linear relationship with a slope of 1.0 for the plot of log flow rate vs log pressure drop across the flow meter, in accordance with the Hagen-Poiseuille equation. The analysis of the gas was determined in the same manner as was reported previously. Good checks were obtained between the composition of the gas established by the flow-meter settings and by chemical analysis of the gas taken after the mixing bulb and ahead of the furnace. The pressures of H2S, H2, S2, and HS in the equilibrium gas at temperature were calculated from the following data :3 The pressures of the species S and S8 were negligible for the conditions of the experiments.3 There was no sign of vaporization of ReS2 either by weight loss or deposits in the reaction tube. Thus it is not possible to account for the apparent volatility of the compound reported by Juza and Biltz.2 The inlet gas composition and the calculated equilibrium ratio of PH2 S/PH2 for the "straddle" points of each experiment are shown in Table I. The specimens of metal for the experiment were small clippings of annealed copper (99.9+ pct) sheet 0.005 in. thick that was obtained from Baker and Adamson and of "high-purity" rhenium (99.9+ pct) sheet 0.005 in. thick that was purchased from Chase Brass and Copper Co. A specimen was removed from the apparatus; inspected for the presence of the sulfide, and then stored in a sealed vial. A fresh clipping was used in each measurement. The condition of the surface of each specimen after the experiment is noted in Table I.

Jan 1, 1969

By G. B. Hooper, G. A. Ferguson

The technical capabilities and user-friendliness of the major computer-aided mining design software systems are reviewed. Recent experiences with three systems are outlined to indicate the practical problems that arise. The examples were: Microlynx software from Lynx Geosystems at the Great Dyke platinum mine in Zimbabwe; Lynx software from Lynx Geosystems at a copper mine in central Africa; and PC-MINE software from Gemcom Services at an open-pit gold project in Western Australia. Difficulties in the use of mining design software has led to an alternative approach. Falconbridge, Canada, has developed an integrated mine-planning system on a CAD platform that encompasses ore reserve estimation, stope design, development layout and survey control. Future directions of computer-aided mining design using this basis are discussed. A major advantage of using mainstream software packages, such as spreadsheets, databases and CAD programs, is that most engineers and geologists are experienced in handling such systems in the normal course of their work.

Jan 12, 1992

By M. R. Khalesi, S. Bellec, C. Bazin, D. Hodouin

Batch grinding tests conducted on a gold ore indicated that gold is not randomly distributed within the size fractions of the ground ore. Since gold leaching performances were found to be dependent of the size of the gold carrying particles an integrated gold ore grinding-leaching simulator should incorporate a method to predict the gold size distribution of a ground ore. The paper describes the results obtained from batch grinding tests showing the non random distribution of gold within the size intervals of a ground ore and the initial developments of a grinding model to predict the gold size distribution in a batch grinding product.

Jan 1, 2011

By Frederic Benard

This paper constitutes a preliminary report on experimental work done to date on the anode-furnace treatment of blister copper containing relatively high percentages of nickel. The investigation has not been completed but results obtained to date are considered of sufficient interest to warrant publication. Blister copper treated by the Ontario Refining Co. originates from the Copper Cliff smelter of The International Nickel Company of Canada, of which the former is a wholly-owned subsidiary. The blister as received contains from 0.50 to 1.50 per cent Ni, and in this respect differs from that treated by other refineries on this continent. During the anode-furnace treatment, only a portion of the nickel content is removed, and of the amount remaining in the anodes a varying percentage is found in the anode slimes. This necessitates a more extensive treatment than ordinary nickel-free material. Sometimes it is necessary to repeat roasting and leaching operations several times before the nickel colltent is low enough to permit the slimes to proceed to the dorè furnace. This, besides increasing treatment charges, causes greater selenium stack losses and involves a longer tie-up of precious-metal values. Therefore this investigation was undertaken with the aim of determining the factors influencing the diversion of nickel into the anode sludge. From experience it was known that by keeping the nickel content of anodes at 0.55 to 0.60 per cent maximum a relatively satisfartory slime resulted. One avenue of attack therefore was developing improved elimination in the anode-furnace treatment so that the anode content mentioned above was not exceeded. Another angle was to improve the solubility, during electrolysis, of the nickel constituent in the anodes, thus decreasing the percentage diverted to slimes. . It may be mentioned here that nickel dissolving electrochemically and entering the electolyte presents no difficulty from a treatment standpoint. Both of these approaches were studied and are discussed separately below.

Jan 1, 1943

By Frederic Benard

THIS paper constitutes a preliminary report on experimental work done to date on the anode-furnace treatment of blister copper containing relatively high percentages of nickel. The investigation has not been completed but results obtained to date are considered of sufficient interest to warrant publication. Blister copper treated by the Ontario Refining Co. originates from the Copper Cliff smelter of The International Nickel Company of Canada, of which the former is a wholly-owned subsidiary. The blister as received contains from 0.50 to 1.50 per cent Ni, and in this respect differs from that treated by other refineries on this continent. During the anode-furnace treatment, only a portion of the nickel content is removed, and of the amount remaining in the anodes a varying percentage is found in the anode slimes. This necessitates a more extensive treatment than ordi-nary, nickel-free material. Sometimes it is necessary to repeat roasting and leaching operations several times before the nickel content is low enough to permit the slimes to proceed to the doré furnace. This, besides increasing treatment charges, causes greater selenium stack losses and involves a longer tie-up of precious-metal values. Therefore this investi-gation was undertaken with the aim of determining the factors influencing the diversion of nickel into the anode sludge. From experience it was known that by keeping the nickel content of anodes at 0.55 to 0.60 per cent maximum a relatively satisfactory slime resulted. One avenue of attack therefore was developing improved elimination in the anode-furnace treatment so that the anode content mentioned above was not exceeded. Another angle was to improve the solubility, during electrolysis, of the nickel constituent in the anodes, thus decreasing the percentage diverted to slimes. It may he mentioned here that nickel dissolving electrochemically and entering the electolyte pre-sents no difficulty from a treatment standpoint. Both of these approaches were studied and are discussed sepa-rately below.

Jan 1, 1938

By Frederic Benard

This paper constitutes a preliminary report on experimental work done to date on the anode-furnace treatment of blister copper containing relatively high percentages of nickel. The investigation has not been completed but results obtained to date are considered of sufficient interest to warrant publication. Blister copper treated by the Ontario Refining Co. originates from the Copper Cliff smelter of The International Nickel Company of Canada, of which the former is a wholly-owned subsidiary. The blister as received contains from 0.50 to 1.50 per cent Ni, and in this respect differs from that treated by other refineries on this continent. During the anode-furnace treatment, only a portion of the nickel content is removed, and of the amount remaining in the anodes a varying percentage is found in the anode slimes. This necessitates a more extensive treatment than ordinary nickel-free material. Sometimes it is necessary to repeat roasting and leaching operations several times before the nickel colltent is low enough to permit the slimes to proceed to the dorè furnace. This, besides increasing treatment charges, causes greater selenium stack losses and involves a longer tie-up of precious-metal values. Therefore this investigation was undertaken with the aim of determining the factors influencing the diversion of nickel into the anode sludge. From experience it was known that by keeping the nickel content of anodes at 0.55 to 0.60 per cent maximum a relatively satisfartory slime resulted. One avenue of attack therefore was developing improved elimination in the anode-furnace treatment so that the anode content mentioned above was not exceeded. Another angle was to improve the solubility, during electrolysis, of the nickel constituent in the anodes, thus decreasing the percentage diverted to slimes. . It may be mentioned here that nickel dissolving electrochemically and entering the electolyte presents no difficulty from a treatment standpoint. Both of these approaches were studied and are discussed separately below.

Jan 1, 1943

By Frederic Benard

THIS paper constitutes a preliminary report on experimental work done to date on the anode-furnace treatment of blister copper containing relatively high percentages of nickel. The investigation has not been completed but results obtained to date are considered of sufficient interest to warrant publication. Blister copper treated by the Ontario Refining Co. originates from the Copper Cliff smelter of The International Nickel Company of Canada, of which the former is a wholly-owned subsidiary. The blister as received contains from 0.50 to 1.50 per cent Ni, and in this respect differs from that treated by other refineries on this continent. During the anode-furnace treatment, only a portion of the nickel content is removed, and of the amount remaining in the anodes a varying percentage is found in the anode slimes. This necessitates a more extensive treatment than ordinary nickel-free material. Sometimes it is necessary to repeat roasting and leaching operations several times before the nickel content is low enough to permit the slimes to proceed to the doré furnace. This, besides increasing treatment charges, causes greater selenium stack losses and involves a longer tie-up of precious-metal values. Therefore this investigation was undertaken with the aim of determining the factors influencing the diversion of nickel into the anode sludge. From experience it was known that by keeping the nickel content of anodes at 0.55 to 0.60 per cent maximum a relatively satisfactory slime resulted. One avenue of attack therefore was developing improved elimination in the anode-furnace treatment so that the anode content mentioned above was not exceeded. Another angle was to improve the solubility, during electrolysis, of the nickel constituent in the anodes, thus decreasing the percentage diverted to slimes. It may be mentioned here that nickel dissolving electrochemically and entering the electolyte presents no difficulty from a treatment standpoint. Both of these approaches were studied and are discussed separately below.

Jan 1, 1938