References of "Gaydardzhiev, Stoyan"
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See detailMagnetically supported zeolite adsorbents for effluent treatment
Pramatarova, R.; Gaydardzhiev, Stoyan ULg

in Gaballah, Hager and Solozabal (Ed.) REWAS’99 - Proceedings of the Global Symposium on Recycling, Waste treatment and Clean Technology, San Sebastian, Spain, 2469-2474. (1999)

Zeolite adsorbents packed in magnetic carrier beds have been used for metals removal from synthetic multielemental effluent solution. Prolonged operation of the bed at high mass transfer rates and good ... [more ▼]

Zeolite adsorbents packed in magnetic carrier beds have been used for metals removal from synthetic multielemental effluent solution. Prolonged operation of the bed at high mass transfer rates and good regeneration degree have been achieved. Some of the loaded zeolite samples have been subjected to X-ray mapping for revealing the adsorption mechanism. [less ▲]

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See detailMicroscopic and laser granulometric analyses of hydrating cement suspensions
Lilkov, V.; Dimitrova, E.; Gaydardzhiev, Stoyan ULg

in Cement & Concrete Research (1999), 29

The results from microscopic and laser granulometric analyses of hydrating cement suspensions, containing active mineral additives are presented. Conclusions are drawn about the specific hydration ... [more ▼]

The results from microscopic and laser granulometric analyses of hydrating cement suspensions, containing active mineral additives are presented. Conclusions are drawn about the specific hydration processes of the investigated cements, as well as the applicability of laser granulometry for the study of cement and hydration products. [less ▲]

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See detailApplication of zeolite minerals as an in-situ amendments for heavy metals polluted soils
Gaydardzhiev, Stoyan ULg; Atanasov, S.

in Pasamehmetoglu and Ozgenoglu (Ed.) Proceedings of SWEMP’98, International Symposium (1998)

Metal fixation from simulated rain water onto zeolite adsorbents has been studies using a column filtration mode. Further on, soil artificially contaminated with heavy metals have been brought into ... [more ▼]

Metal fixation from simulated rain water onto zeolite adsorbents has been studies using a column filtration mode. Further on, soil artificially contaminated with heavy metals have been brought into contact with the zeolites. The loaded adsorbents have been studied via IR spectroscopy wih the aim to reveal the predominant mechanism of metal uptake. [less ▲]

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See detailHydrometallurgy of precious metals - effects on the environment
Gaydardzhiev, Stoyan ULg

in Gallios and Matis (Ed.) Proceedings of a NATO-ASI, NATO-ASI Series 2, v. 43 (1998)

Factors which affect the release of toxic substabces to the environment during the hydrometallurgical processing of precious metals bearing ores are discussed. The environmental notions of the cyanidation ... [more ▼]

Factors which affect the release of toxic substabces to the environment during the hydrometallurgical processing of precious metals bearing ores are discussed. The environmental notions of the cyanidation process are presented together with a review about the work in the field of alternative gold lixiviants. [less ▲]

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See detailCoal-gold agglomeration of alluvial gold
Gaydardzhiev, Stoyan ULg; Kireva, R.; Stoev, S.

in Kemal, Arslan, Akar and Canbazoglu (Ed.) Proceeding of VI-th International Mineral Processing Symposium (1996)

The study concerns feasibility testing of the coal-gold agglomeration process as alternative to the amalgamation for upgrading of alluvial gold fractions found in a dredge line. Different process ... [more ▼]

The study concerns feasibility testing of the coal-gold agglomeration process as alternative to the amalgamation for upgrading of alluvial gold fractions found in a dredge line. Different process parameters such as oild and coal type, coal/oil and agglomerates/gold ratio have been varied with the aim to optimise the degree of gold recovery. The addition of quartz and heavy mineral particles in the slury in view outlining process selectivity is also discussed. [less ▲]

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See detailOpportunities for using two low-cost methods for treatment of metal bearing aqueous streams
Gaydardzhiev, Stoyan ULg; Hadjihristova, M.; Tichy, R.

in Minerals Engineering (1996), 9

The feasibility of two non-traditional approaches - reedbeds as a natural wetland and adsorption on lignite and its maceral fractions - for their application in metal bearing effluent treatment is ... [more ▼]

The feasibility of two non-traditional approaches - reedbeds as a natural wetland and adsorption on lignite and its maceral fractions - for their application in metal bearing effluent treatment is discussed. The main mechanisms of metals uptake are otulined. The preliminary results from a pilot scale wetland operation for metallurgical effluents purification are analysed. For the second approach - the different maceral fractions derived from coal refining have shown different metal uptake apptitude. Zeta potential studies and adsorption isotherms have explained these findings. [less ▲]

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See detailVibro assisted cementation of gold onto zinc granules
Gaydardzhiev, Stoyan ULg; Stoev, S.

in Proceedings of the 14-th Mining Congress of Turkey (1995)

Cementation of gold aqueous complexes onto zinc granules instead of zinc dust was studied in a column subjected to vibrations. Two type of lab csale cementing reactors were tested and their efficiency ... [more ▼]

Cementation of gold aqueous complexes onto zinc granules instead of zinc dust was studied in a column subjected to vibrations. Two type of lab csale cementing reactors were tested and their efficiency compared a column and a bed-type one. The influence of foreign ions addition upon the degree of gold cementation was investigated as well. [less ▲]

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See detailSeparation by ultrasonic degassing of flotation pulps
Gaydardzhiev, Stoyan ULg; Stoev, S.

in Demirel & Ersayin (Ed.) Proceedings of 5-th International Mineral Processing Symposium, Cappadocia, Turkey (1994)

An ultrasonic impact on a gas saturated flotation pulps has been investigated with the aim to generate bubbles in alternative to the classical way - i.e. instantly onto the surface of the mineral ... [more ▼]

An ultrasonic impact on a gas saturated flotation pulps has been investigated with the aim to generate bubbles in alternative to the classical way - i.e. instantly onto the surface of the mineral particles. A mciro flotation cell and pure minerals have been used for this purpose. Faster kinetics and reduced reagent consumption could be pointed out as main advantage of the studied approach. [less ▲]

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See detailOpportunities for fine gold recovery from a copper flotation circuit using Knelson concentrator
Patchejieff, B.; Gaydardzhiev, Stoyan ULg; Lazarov, D.

in Minerals Engineering (1994), 7(2/3), 405-408

Experiments aimed at determination of the character of the gold observed in a copper ore processed by flotation, and also to evaluate the possibilities of improvement of the total gold recovery have been ... [more ▼]

Experiments aimed at determination of the character of the gold observed in a copper ore processed by flotation, and also to evaluate the possibilities of improvement of the total gold recovery have been carried out. The gravity equipment used was a 7.5" Knelson screen hydrostatic concentrator, reported of being capable of treatment and upgrading of up to 1000 times raw material with about 30% hypothetical concentration of heavy flotation sized particles. The gold-to-sulfides ratio obtained during the various runs was chosen as a general criterion for the type of gold presented (free or locked) and for the gravity approach feasibility. [less ▲]

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See detailPossibilities for rutile extraction from Norwegian eclogite by flotation
Gaydardzhiev, Stoyan ULg; Sandvik, Knut

Scientific conference (1993)

Preliminary flotations tests towards rutile extraction from Norwegian eclogites (Verving deposit) have been carried out. Various sulfonate type flotation reagents (produced by Hoechts) have been tested ... [more ▼]

Preliminary flotations tests towards rutile extraction from Norwegian eclogites (Verving deposit) have been carried out. Various sulfonate type flotation reagents (produced by Hoechts) have been tested. Selectivity between rutile/pyroxene has been targeted. Rutile separation from pyrite and garnet has been further identified as principal problem. [less ▲]

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See detailPerspectives for treatment of precious metals containing flotation wastes
Gaydardzhiev, Stoyan ULg

in Rao, S.; Amaratunga, L. (Eds.) Waste Processing and Recycling in Mining and Metallurgical Industries (1992, August)

Four groups of precious metals containing mineral resources occuring in Bulgaria are described. The precious metals which they contain are often lost in the tailings during flotation since the exisitng ... [more ▼]

Four groups of precious metals containing mineral resources occuring in Bulgaria are described. The precious metals which they contain are often lost in the tailings during flotation since the exisitng schemes are targeting the recovery of non-ferrous metals mainly. Options for recovery of the thus remaining precious metals by cyanidation and thiourea leaching are discussed and preliminary results presented. [less ▲]

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See detailThe use of native brown coals - sorbents in controlling the environmental impact of heavy metals containing mine waters
Gaydardzhiev, Stoyan ULg

in Proceedings of the International Symposium on Environmental Contamination in Central and Eastern Europe (1992)

The possibilities for qualitative evaluation of removal of heavy metals from hydrometallurgical leach solutions using brown coal as sorbent have been tested. Factorial analysis to show the influence of ... [more ▼]

The possibilities for qualitative evaluation of removal of heavy metals from hydrometallurgical leach solutions using brown coal as sorbent have been tested. Factorial analysis to show the influence of coal type, coal particle size, sorbent amount and contact time on the degree of precious metals removal from solution has been used. [less ▲]

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See detailAdvantages of natural brown coal application for sorption treatment and cleaning of pregnant solutions after thiourea leaching
Gaydardzhiev, Stoyan ULg

in Chalkley, M.; Oliver, A. (Eds.) Proceedings of the International Symposium of Environmental Controls in Metallurgical Industries and Scrap Metal Recycling (1991, August)

The possibility for metals sorption on native brown coal has been tested using pregnant solutions obtained aftet thiourea leaching of flotation wastes. Two stage sorption flowsheet has been designed ... [more ▼]

The possibility for metals sorption on native brown coal has been tested using pregnant solutions obtained aftet thiourea leaching of flotation wastes. Two stage sorption flowsheet has been designed. Precious metals could be recovered from the loaded sorbents by burning them. Sorbent amount, sorption capacity and contact time have been investigated in terms of influence on process feasibility. [less ▲]

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