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By V. Bondarenko

The importance and necessity of gas hydrates deposits development followed by natural gas extraction is considered in the present paper. Analysis is given to world sources focused on methane hydrates formation conditions. Information covering the most perspective gas hydrate deposit of the Black Sea is presented in the article. Two most common methods of gas hydrates development ? thermo stimulation and inhibitor injection are analyzed presenting their comparative characteristics. Basic scientific trends and developments of underground mining department in the field of gas methane extraction from gas hydrates are scrutinized. Schemes and methods of natural gas hydrates development are shown together with formulas, parameters and factors influencing the extraction process. Also the analysis is given to the possibility of gas hydrates formation from methane-air mixtures of degassing wells from coal mines of Ukraine. Improved experimental unit for gas hydrates formation under laboratorial conditions is presented with its basic characteristics. General conclusions and basic tasks requiring further research are given in the end.

Aug 1, 2013

By D. R. BUDINSKI

Clinton Creek Mine in west-central Yukon produced 0.94 million tonnes of fibre from 15 million tonnes of asbestos ore between 1968 and 1978. The mine closed in 1978. The deposit lies along the margin of a medium sized ultramafic pluton that intrudes schistose and gneissic rocks of the Yukon Metamorphic Complex. Country rocks are metamorphic equivalents of a mixed sedimentary and volcanic assemblage deposited during Precambrian or early Paleozaic time. Movement along the north west-trending Tintina Fault System probably caused the fairly high meromorphic grade that altered the original rocks to schists and gneisses. The ultramafic pluton hosting Clinton Creek Mine is one of several bodies that were emplaced along a deep seated imbricate fault system parallel to the Tintina Trench. Most of rhe intrusions were hydrothermally altered to serpentinite, bur apparently only the one at Clinton Creek contains commercial quantities of asbestos. The Clinton Creek pluton was probably injecred slowly at relatively low temperatures into the crustal rocks as a "mush" that cooled gradually, allowing sufficient time for serpentinization and chrysotile fibre crystallizarion.

Jan 1, 1984

By T. Gerritsen, C. Martinez, F. Stober, T Ma, J. R. Frias, M. Sedighy, J. Janzen

Electrode control systems regulate power by physically positioning electrodes. Due to the weight and inertia of the electrodes and hoist equipment, this is a relatively slow process where power fluctuations of less than a few seconds are not fully corrected. Nickel laterite AC furnaces operating in high voltage, shielded arc mode typically incur frequent power variations of approximately +/- 20% or more around the power set point. To provide enhanced power control, Hatch has recently supplied, at commercial scale, a thyristor-switched reactance system called an SPLC. The SPLC incorporates predictive control software to operate furnaces at the maximum transformer rating by reducing the large power swings experienced without the SPLC. The resulting higher average power enables higher production, without increasing transformer or power plant capacity. A 60 MW production version of the SPLC has been commissioned on Falconbridge Dominicana's laterite nickel furnace, yielding excellent results with a 3 to 1 reduction in power fluctuations.

Jan 1, 2005

By S. Aram

Concrete reinforcing requires coordination among many roles: structural engineer, estimator, detailer, fabricator, installer and others. The methods used to define and represent concrete reinforcement elements and assemblies in building information models is crucial in determining the efficiency of sharing data among BIM platforms and the effectiveness of using the carried data in production planning, fabrication and site work activities. Starting from the information items that are required to be provided by BIM platforms, as defined in earlier work, we have developed the Industry Foundation Classes (IFC) bound Concepts and Model View Definitions (MVDs) for concrete reinforcement. Furthermore, in coordination with software developers, we propose guidelines for best practices for concrete reinforcement modeling. Implementing these guidelines by software providers will improve reinforcement modeling with regard to various aspects of reinforcement products like geometric representation, placement, and property specifications. The proposed approach is selected as a way to improve functionality of the shared data for production planning, fabrication, project management, and site activities. Guidelines for assigning information to rebar type and instance definitions as well as to rebar elements and assemblies are provided. An efficient method of sharing geometry and property sets among rebar instances of a rebar array is also defined.

Aug 1, 2013

By S. E. Wolfe

AKNOWLEDGE of the density of a pulp or suspension is frequently required by the millman, to whom fluctuations in density, which occur in all mill circuits, are of importance and interest. There ,are many w.ays currently in use to determine density and probably the most common method is to take samples of the pulp. The proper sampling of the material is no easy matter, particularly when the pulp contains a sand fraction which settles rapidly. For example, when filling a liter container from the overflow of a classifier, it is al-most impossible to fill the can completely and yet prevent overflow. If there is an overflow, the pulp remaining in the can invariably has an excess of sand and the indicated density will be too high. To surmount such difficulties, and to obtain a continuous indication of the density of a pulp at any desired depth, the simple indicator shown diagrammatically in Figure l was designed by the writer in 1951. Its component parts, numbered as in Figure 1, are as follows.

Jan 1, 1958

By H. H. Bleakney

THIS paper presents evidence that in 3 1/2% nickel steel, the published temperature for the Ac1 transformation, l,275°F., represents the completion of that transformation, and that its inception occurs approximately 275°F. lower, at about l,000°F. The formation of austenite within this range, especially at the higher temperatures, and its subsequent decomposition to martensite, results in considerable impairment of the properties of the steel. That the solid solution found to occur below l,275°F. is austenite has been questioned, but the evidence herewith presented, while not decisive, appears to be reasonably convincing. INTRODUCTION The February, 1939, issue of Metals Technology contains a very interesting paper by I. N. Zavarine, Associate Professor of Metallurgical Engineering at the Massachusetts Institute of Technology. In that paper, Professor Zavarine presented photomicrographs illustrative of the microstructures produced by heating nickel steels to a temperature slightly below the carbon change point, and holding them at that temperature for various lengths of time. His illustrations show that the structures found after such treatment do not consist merely of ferrite and carbides, but are characterized by the presence of a third phase, which he describes as a' 'sub-critical solid solution'. The occurrence of this third phase in increasing amounts is accompanied by an increase in strength and a loss of ductility and impairment of elastic ratio of the steel. Some years ago, one of the authors encountered the above-mentioned phenomenon in treating large forgings of 3.5% nickel steel. After normalizing and then drawing at l,250°F., very poor mechanical properties were obtained. Investigation of the steel disclosed no inferiority in quality. Eventually, after considerable waste of time and money, a draw temperature of l,150°F. was tried. This treatment resulted in a very great increase in elastic ratio, over 5 per cent increase in percentage elongation, and proportionate improvement in reduction of area.

Jan 1, 1941

By Abhilash

Uranium is conventionally extracted using a process that employs strong acid (H2SO4) and an oxidant (MnO2) as leaching agents. This method often creates environmental problems, requires large amounts of energy, and involves a complex operational plant. It is not, however, economically attractive to extract uranium from low-grade ores by chemical leaching. Because the content of U3O8 in the Indian ore is usually below 0.1% by weight, it is necessary to develop an alternative process to enable the efficient and economic recovery of uranium. Uranium ore from the Narwapahar mines, UCIL is a type of vein deposit found in India, which accounts for ~54% in India. The ore (0.047% U3O8), though of Singhbhum area, possess exceptionally different mineralogy due to presence of some refractory minerals and richness of apatite (5%) resulting in a maximum 78% recovery through conventional processing at UCIL, with a very high consumption of sulfuric acid and pyrolusite, besides possible loss of uranium as uranium phosphate. To avoid usage of environmentally non-benign oxidants, remediation of influence of phosphates, and improve the overall process output of uranium; an alternate extraction technology using microbial isolate(s) is worthwhile exploring and the same is presented in the paper. The microbial isolate enriched with Acidithiobacillus ferrooxidans grown from source mine water was employed for bio-leaching of uranium while varying pH, pulp density (PD), particle size, etc. On varying pH at 35oC using 20%(w/v) PD and <75µm particle size, 83.5% and 78% uranium bio-recovery were observed at 1.7 and 2.0 pH in 40 days against maximum recovery of 46% and 41% metal in control experiments respectively. Whereas, it was observed that grinding of ore to finer size actually helped dissolution of uranium. Finer size particles (<45µm) gave a maximum biorecovery of 93% in 40days at 10%(w/v) PD, 1.7 pH and 35oC. The bio-recovery of uranium fell down from 93% to 82.73% and 60% on increasing the pulp density from 10% to 20% and 30% respectively for particles of <45µm size. The higher uranium dissolution during bioleaching at 1.7pH can be correlated with increase in redox potential from 433 mV to 664mV in 40 days.

Aug 1, 2010

By H. L. Cameron

General Statement In July, 1948, experimental aerial photography o shallow water zones on Northumberland strait was carried out by the Nova Scotia Research Foundation. This work was designed to test the feasibility of aerial photography for coastal surveys o various types, including seaweed and bottom detail surveys. In the course of the work at Lismore, undersea faulting was noted visually and was later clearly apparent in the photographs. In order to prove beyond doubt that the lineations photographed are actually faults, a ground check was made, and terrestrial stereoscopic photographs were obtained of these features where they intersect the shore line. There can be no doubt of their nature, and the type of faulting is probably thrusting due to compressive forces. This is indicated by the successive right- and left-hand displacements on intersecting faults. The age of the fracturing is post Lower-Pennsylvanian (Lismore) and is correlated with similar compression faulting in western Cape Breton. As far as can be ascertained, this is the first time that subsea faulting has been photographed, though it is quite possible that similar structures have been observed elsewhere. Location and Area Lismore is on Northumberland strait, approximately thirty-five miles east of Pictou (see index map, Figure 1). The area mapped from aerial photographs (Figure 2) is a strip approximately two miles long by a quarter of a mile wide. Figure 3 shows a stereo-pair of the aerial photographs used to construct this map. The terrestrial stereoscopic photographs (Figure 4) show one of the faults.

Jan 1, 1949

By G. Binks

In 1997, the Zinifex Hobart Smelter ceased ocean disposal of jarosite and the flowsheet was converted to reject iron as paragoethite. This paper describes the evolution of the flowsheet since the changeover and considers future flowsheet developments. The major change to the flowsheet has been an increase in the silica content of the calcine resulting from treating increasing levels of Century concentrate. The high silica levels impacted on the paragoethite precipitation stage, causing a deterioration in the settling and filtration characteristics of the paragoethite and an increase in the contained zinc level. The implementation of a two stage neutral leach step has enabled the flowsheet to cope with the higher input silica levels. Future developments include an understanding of the form of the zinc in the paragoethite and options to lower the zinc level to improve the overall zinc recovery.

Jan 1, 2006

By W. G. Jewitt

Introduction The use of the aeroplane in prospecting is already familiar to everyone connected with the mining industry. Apart from transportation companies, three organizations, the N. A. M. E., the Dominion Explorers, and the Exploration Department of the Consolidated Mining and Smelting Company, have made the aeroplane an everyday feature in every mining district in Canada. Its use has been demonstrated successfully in the mountains of British Columbia, but perhaps its greatest field lies in the Canadian Shield, where the numerous lakes and rivers afford an almost continuous series of landing places for aeroplanes, on floats in the summer and on skis in the winter. To the man who has travelled by canoe, toiling over fly-infested portages or held for days at a time, wind-bound, on the big lakes, the ease, speed, and cheapness of aeroplane travel have marked the beginning of a new era, in which ground previously covered with difficulty in a month or more is travelled with ease in a few hours. Development of an air service in the Consolidated Mining and Smelting Company has proceeded on different lines from those of other organizations, and this paper is concerned with that development.

Jan 1, 1931

By Hong Zhong, Shuai Wang, Gang Zhao, Lanqing Deng, Guangyi Liu

In this paper, three novel surfactants containing double reactive centers(-CONHOH and –CONH-), double hydrophobic groups were designed and synthesized as collector for separation of diaspore and aluminosilicate minerals, such as N-(4-(hydroxyamino)-4-oxobutyl)octanamide (HA-8), N-(4-(hydroxyamino)-4-oxobutyl)decanamide (HA-10) and N-(4-(hydroxyamino)- 4-oxobutyl) -dodecanamide (HA-12). The adsorption mechanism of N-(4-(hydroxyamino) -4-oxobutyl)alkylamides (HA) onto diaspore was also investigated by FTIR spectra, zeta potential measurement and DFT. The flotation results demonstrated that three collectors all exhibited superior collecting power to diaspore and selectivity against kaolinite and illite, and could effectively realize flotation recovery of diaspore from bauxite ores contained aluminosilicate minerals under neutral conditions. Moreover, HA-12 was a superior collector than other two collectors for bauxite separation. The results of XPS, FTIR spectra and zeta potential illustrated that at around pH 6.0, HA might chemisorb on diaspore surfaces through Al-O coordination bonds formed by binding its –C(=O)NHOH or –C(=O)NH– chelate groups with aluminum atoms on diaspore surfaces. HA’s unique properties, such as characteristic bond patterns onto diaspore surfaces, double hydrophobic groups, and intermolecular hydrogen bonds between neighboring HA molecules coated on diaspore surfaces, rendered it to be a superior flotation collector for diaspore.

Jan 1, 2016

By Lihong

A series of Fe2O3-elimination experiments were conducted on feldspar samples from Tangshan Stone?powder Plant. These experimental methods include scrubbing desliming, flotation,rod milling and high gradient magnetic separation. Some technical factors of feldspar concentration and a new technological flow?sheet of ceramics raw material concentration were put forward.

May 1, 2003

By R. F. Sharpe

THE Bullion mine, in the famous Cariboo district of British Columbia, is situated on the left bank of the South fork of the Quesnel river, approximately three miles below the outlet of Quesnel lake. A good road leads 63 miles northeast to the property from Williams lake, the railhead on the Pacific Great Eastern railway. The mine may also be reached over good roads from Vancouver via the Fraser canyon, Ashcroft, Clinton, and the 150-mile house, a total distance of 407 miles. In the early days of placer mining on the South fork of the Quesnel, several rich bars were found. The &apos;pay&apos; on one of these at the mouth of Dancing Bill gulch was followed up the gulch by a Chinese company, who proved to be the discoverers of the present Bullion mine. This Chinese company commenced working in 1884, in what was then referred to as the China pit. Although working under very primitive conditions, it is reported that, during the ten years they operated the property, they recovered in excess of $900,000 in gold. This somewhat large recovery was due to a local concentration, the result of Dancing Bill creek having meandered down that portion of the channel and washed off the overburden. In 1894, a syndicate composed largely of the Canadian Pacific Railway directorate of that time, with J. B. Hobson as their field manager, acquired the property, as the apparent magnitude of the operation was too great for the resources of the Chinese company. Mr. Hobson, during the first ten years of his regime, developed the mine into a large-scale hydraulic operation, and during that period, from 1894 to 1905, recovered approximately $1,234,000 in gold. In 1906, the property was sold to the Guggenheim Exploration Company, who retained Mr. Hobson as Manager and embarked on an extensive programme to bring in additional water. This project was never completed, however, work being suddenly abandoned in 1907 and the mine closed down. Shortly afterwards, the property was purchased by a small operator on what is believed to have been largely borrowed capital. This venture resulted in no production, but in much litigation, which eventually reached the Privy Council in 1920.

Jan 1, 1939

By R. Kaibyshev, I. Zuiko

"The effect of thermomechanical processing (TMP) including cold working by tension or rolling before aging on mechanical properties and a dispersion of secondary phase particles of an AA2519 alloy (Al–5.64Cu–0.33Mn–0.23Mg–0.15Zr–0.11Ti–0.09V–0.08Fe–0.01Si (wt. %)) was examined. It was shown that the use of tension to impart pre-strain =10% in the alloy provides the best combination of properties in peak aging condition of the material. The AA2519T87 alloy processed by tension exhibits the yield stress, ultimate tensile strength and elongation to failure of 425.4±2.4, 475±2.4, 12.1±0.4, respectively. The one pass rolling leads to -5% decreases in yield stress and –20% decreases in ductility. Dislocations serve as heterogeneous nucleation sites for ?'-phase precipitation. The positive effect of tension is attributed to the formation of more homogeneous dislocation structure, uniform distribution of ?'-phase particles with higher aspect ratio. Precipitation of the O–phase plates on {111}a habit plane was detected. In addition it was shown that the low angle boundaries are heterogeneous nucleation sites for ?' and O particles.INTRODUCTION Precipitation-hardened alloys are a commercially important group of the materials because their mechanical properties can be modified by treating and changing the microstructure. Age-hardenable aluminum alloys belonging to the Al–Cu–Mg system are widely used due to their attractive combination of high specific strength, good fracture toughness and enhanced creep resistance attributed to the highly efficient strengthening by the ?'-phase (Palmer, StJohn, Nie, & Qian, 2017). An AA2519 alloy exhibiting superior mechanical properties among high-strength Al–Cu alloys (2XXX-serie) due to minor Mg additives. It is known that, in alloys with high Cu/Mg ratio (=5.6) the classic precipitation sequence (Palmer et al., 2017; Wang & Starink, 2005; Wang et al., 2010) of supersaturated solid solution (SSSS) decomposition occurs: SSSS ? GP zones (Al3Cu) ? ?? (Al3Cu) ? ?' (Al2Cu) ? ? (Al2Cu) (1)"

Jan 1, 2018

By Dan Zou, Ji Chen, Deqian Li

"Bayan Obo mixed RE concentrate is the largest RE source in the world. RE elements occur dominantly in bastnaesite and monazite. This paper describes a clean and green technique for processing Bayan Obo mixed rare earth (RE) concentrate. A two-step oxidation method can lead to the effective recovery of REs, thorium (Th), fluorine (F) and phosphorus (P). Ce has a property of valency change, enabling the separation of it from other RE(III) elements. Making use of the interactions of cerium (IV) (Ce(IV)), F and P, a new extraction system was created to separate Ce(IV) effectively from other RE(III) while recovering F, P and Th by complexing F and P following the oxidation of Ce(III) to Ce(IV). The method includes two parts. Firstly, bastnaesite is oxidized by air roasting and sulfuric acid leaching. And then a first leach liquor containing Ce(IV), F and P is obtained. Secondly, monazite was converted into REhydroxide through alkaline attack and then Ce(III) in the RE-hydroxide was oxidized into Ce(IV) by wetair oxidation. After sulfuric acid leaching the oxidized RE-hydroxide, a second leach liquor is obtained. The two parts of leach liquor containing Ce(IV), F and P are then extracted by Cyanex923 to obtain CeO2, CeF3 and CePO4 based on the complex of Ce(IV) with F and P. The raffinate was further extracted by the primary amine N1923, and Th-product was recovered as ThO2. The RE elements recovery yield during the whole process is greater than 92%. The new technique not only provides a new way for Bayan Obo RE ore utilization, but also avoids resource waste and environment pollution.INTRODUCTIONRare Earths (REs) refer to lanthanides, including scandium and yttrium. Owing to the similar structure and property of RE(III), it is difficult to separate them from each other, especially for the adjacent elements. According to the United States Geological Survey, in 2010, the whole world has about 142 million tonnes of rare earth reserves. In that, China ranks the second with 22% following Brazil which ranks first with 32% (Cheng, 2011). There are three main RE ore types in China with about 80% mixed ores in Bayan Obo, 10% bastnaesite ores in SiChuan and ShanDong province and 2.9% ion adsorption ores in Southern China. Bayan Obo mixed RE concentrate consists of bastnaesite and monazite. The concentrate contains CeO2/_REO of 50% and there are 7–8% F, 4-6% P and 0.2–0.3% Th."

Jan 1, 2016

By G. Roy

Interest in metal-hydrogen systems can be manifold. Small amounts of hydrogen adsorbed by elemental metals and alloys usually result in strong changes in the physical and mechanical properties of engineering materials. Overwhelmingly, these changes, viz. hydrogen embrittlement, are considered deleterious with respect to structural performance of engineering materials. However, the changes, often studied by metallurgists and metal physicists, can present new possibilities and applications. A prominent example is the recent interest in safe, solid-state hydrogen storage in metallic lattices. In a new laboratory in MTL, Ottawa, a study has been initiated to investigate the effect of "micro- and macro- alloying" of Al and Mg powders with hydrogen (in high-energy mechanical alloying mills) on plastic deformation in metal and metal hydride structures. It is anticipated that high-rate impacting and subsequent grain refinement in the mill will have an effect on hydrogen storage capacity in lightweight magnesium and aluminum alloys. First examination of the state-of-stress by X-ray diffraction in high-rate milled, nanostructured pure aluminum, aluminum milled with a solid surfactant, and aluminum or magnesium alloy milled with hydride and/or gas hydrogen will be presented.

Jan 1, 2005

By Y. Jin, H. You, H. Pang, B. Lin

Successful application of steam assisted gravity drainage (SAGD) on the recovery of land facies ultra-heavy oil in Xinjiang oilfield depends largely on shortening the preheating period with the aid of the micro-fracturing technology, which is conducted through controlled water injection to a pair of horizontal wells to create homogenously distributed microcracks in the zone between the two wells. The numerical simulation of this mechanical process is yet to be investigated. Up to date, there has been research work on rock mechanics during the SAGD production period of marine deposited ultra-heavy oilsands, but the counterpart research on land facies ultra-heavy oilsands of Xinjiang oilfield is left undone. In this regard, this study is attempted to perform numerical simulation of the fracturing process on land facies unconsolidated oilsands. With this objective, the study first investigates geological and physical identification of the field collected cores, then carries out mechanical analysis on laboratory triaixal test results, based on which numerical simulation of the fractured zone is performed. The simulation is applied through a finite element platform adopting extended Drucker-Prager constitutive model, with the parameters determined by experimental work. It is verified that hydraulic fracturing of unconsolidated oilsands generates a microcrack feature in terms of a dilative zone instead of linear apertures. The extent to which the fractured zone propagates is visually demonstrated based on the magnitude distribution of equivalent plastic strain or volumetric dilation. Evaluation of the connection of injection and production wells can possibly be determined by the expansion of the saturated region around each well. Finally, the implications on the efficiency of hydraulic fracturing in stimulation of the pay zone are investigated.

Jan 1, 2015

By Lin-fang Shen, Shao-jun Li, Zhi-liang Wang

"The meso-structure of real soil consists of numerous particles with different sizes, while the traditional reconstruction method of quartet structure generation set (QSGS) produce relatively uniform soil particles resulting in significant discrepancy between the actual structure and reconfiguration model. In order to remedy the deficiency, the QSGS is improved by considering the influence of porosity and autocorrelative function of soil, which make the models closer to the real soil. Based on the reconfiguration model, Lattice Boltzmann method is combined in the algorithm to conduct further simulation of fluid flow in soil pores. The D2Q9 model is applied to construct the two dimensional model for simulating mesoscopic seepage field of saturated soil by setting the non-equilibrium extrapolation scheme at the inlet and outlet boundary, and the bounce-back scheme at the soil particles boundary as well as the left and right boundary. According to the case study, the proposed program is realized to simulate mesoscopic seepage field of reconstructed soil with constant inlet seepage velocity. The results show that the seepage direction of soil is along the passage with good connectivity, therefore the permeability is controlled by these passages. The seepage velocity in such channels is faster than in bad connectivity channels. Even if the channel has larger pores, the seepage velocity is still small. INTRODUCTIONUnderstanding the seepage mechanism in porous materials is significant in both theoretical and engineering problems. As a typical porous media, soil consists of solid particles and voids, which form connected channels allowing water to flow through. Such seepage in soil exists widely among geotechnical project of slope, foundation pit, and tunnel, etc. Meanwhile, a number of engineering accidents are caused by limited knowledge of seepage characters in soil (Huang, 2006; Liu, 2013). The conventional method in describing seepage features mostly based on the parameter of permeability, which is a macro statistic mean evaluating the whole connectivity of soil. Obviously, this parameter cannot exactly reflect the details of how water flows through the inner soil structure, especially the flow velocity in local mesoscopic area, hence is unable to represent the actual seepage properties. Therefore, it is necessary to develop mesoscopic approaches to fully study the seepage mechanisms."

Jan 1, 2015

By L. Xia, B. Hart, K. Douglas1, S. C. Chelgani

Development work to optimize a flotation flowsheet for rare earth element (REE) recovery is underway. The original approach used alkyl phosphates and phosphoric acid ester as collectors to concentrate REE minerals. To improve REE recovery, hydroxamates as alternative collectors were investigated. In this paper, micro flotation of REE minerals using salicylic, benzoyl and naphthoyl hydroxamates is reported. Unlike phosphonic collectors, slime removal does not show a significant effect on REE recovery when using hydroxamates as collectors. Among the three hydoxamates, the grade of La, Ce, and Nd for concentrates produced by salicylic hydroxamate is the highest. The recovery response with naphthoyl hydroxamate is similar to that of salicylic hydroxamate; good grades for La, Ce, and Nd, less effective for Nb, Y, and Zr. The data indicated an affinity by salicylic and naphthoyl hydroxamtes for LREE over the HREE minerals. In comparison, benzoyl hydroxamate indicated an affinity for Nb, Y, and Zr. Temperature effects on REE recovery were also studied. The grade and recovery of REEs generated by flotation using a mix of salicylic and benzoyl hydroxamates at room temperature was almost identical or even better relative to the recovery using naphthoyl hydroxamates at elevated temperature.

Jan 1, 2014

By Z. D. Hora

Limestone of economic interest is widespread in British Columbia. Triassic deposits on Texada Island are a convenient 1idewa1er source of li111es1one for cemen1 and lime for 1he Pacific orthwes1. Permian limes/one near Pavilion Lake is used for quicklime, and a deposit near Kam/oops is used for cement. Quarries at Dahl Lake and Pwrmigan Creek serve local pulp and paper needs.

Jan 1, 1984