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Senovo, Bulgaria

Prokopiev A.,Kaolin AD | Popov N.,Mineralagro Z Ltd. | Chakalov K.,Romb Ltd. | Popova N.,Romb Ltd. | And 2 more authors.
26th International Mineral Processing Congress, IMPC 2012: Innovative Processing for Sustainable Growth - Conference Proceedings | Year: 2012

The biological stage of reclamation is the third final stage in remediation the damaged mining terrains, which is carried out following the completion of the mining technical stage. The biological stage of reclamation is carried out through restoration of the vegetation layer. The biological reclamation includes all activities related to the introduction into the terrain of vegetation, microorganisms, insects, and animals, with the acceleration of the succession and creating conditions for a sustainable ecosystem close to the natural one. It comprises of all anti erosion and other activities such as the preparation of the land for growing agricultural crops, sowing grass seeds, planting seedlings, amelioration of the soil and further care for the vegetation until its final place on the land. Mineral and organic-mineral ameliorants for biological reclamation were studied. The basic mineral ameliorant is Bulgarian natural zeolites. The zeolitic-rich tuff samples provided from Golobradovo deposit was characterized by their chemical and mineralogical composition and ion exchange properties and X ray analysis. The average content of clinoptilolite was found to be more than 80%. The materials had ion exchange capacity (NH4+) varying from 100 to 110 meq/100g. Chemical modifications of natural clinoptilolites were made in order to form active phases of nitrogen, phosphorus, potassium, and microelements. Slow-acting mineral ameliorant was developed. Organic-zeolite substrate for biological reclamation was developed. This new product is a mechanical mixture of organo-matter and modified zeolites. Agro-chemical parameters of new ameliorants were determined. The substrates including studied overburden dump soil and mineral or organo-mineral ameliorants are produced. The grass growth test was performed.

Marinov M.,Kaolin AD | Valchev A.,Kaolin AD | Grigorova I.,University of Mining and Geology St Ivan Rilski | Nishkov I.,University of Mining and Geology St Ivan Rilski
26th International Mineral Processing Congress, IMPC 2012: Innovative Processing for Sustainable Growth - Conference Proceedings | Year: 2012

The Bulgarian deposits of quartz-kaolin raw materials are localized in the NE Bulgaria. For many years, the quartz-kaolin sand separation has been performing by water washing technology. After wet separation the raw material yields two products - washed kaolin (different grades) and quartz sand (different grades). Research and development program has started to improve the quartz-kaolin sand separation. The program has undertaken an increasing of processing capacity, to decrease the losses in the tailings and to provide production of new quartz sand grades. The kaolin-silica raw materials from Vetovo open mine and the technological tailings from Vetovo processing plant were characterized. It was established that there are a lot of losses of quartz in final tailings. New approach on kaolin-silica raw material separation was tested in laboratory scale. The test work was performed on Derrick Stacksizer screening machines. The results of laboratory experiment show that there are possibilities to increase the quartz sand recovery and to start the production new grade sand. The full-scale pilot test was performed including the following units: two Derrick Stacksizer screening machines equipped with 0.430 mm and 0.150 mm opening Derrick Urethane Panel, respectively; Flat bottom DN 500 Hydrocyclone and DN 100 Hydrocyclon. The pilot test data clearly demonstrate that the Derrick Stacksizer screening machines are suitable for Bulgarian silica-kaolin raw material. Based on the test data a new quartz-kaolin separation technology was developed. The new technology was introduced in Vetovo processing plant increasing processing capacity and decreasing the losses of quartz in final tailings. Additionally the production of silica sand grade PK 0.16 is increased and starts the production a new grade PK 0.10.

Valchev A.,Kaolin AD | Ignatova T.,Kaolin AD | Grigorova I.,University of Mining and Geology St Ivan Rilski | Nishkov I.,University of Mining and Geology St Ivan Rilski
IMPC 2014 - 27th International Mineral Processing Congress | Year: 2014

Feldspars used by ceramic and glass industries as fluxing agents are mainly obtained from high quality feldspar deposits. The demand for feldspar as raw material for industrial applications especially in ceramic manufactures is continuously increasing. However, due to the depletion of those deposits, the research activities related to the recovery of feldspar from the lower grade feldspar deposits and feldspar bearing rocks such as pegmatite, granite, arkosic sandstone and syenite have been intensified in the last two decade. In Bulgaria, the main deposit of arkosic sandstone is located in the area of Shumen town, NE Bulgaria. In Srednya deposit arkosic sandstones are found in Upper Cretaceous sediments (Santonian). In this formation, there are two major industrial minerals - feldspar and quartz. They may be of economic value and possibly suitable for commercial uses. The main purpose of the present study was to investigate the beneficiation and upgrading processes of Srednya deposit arkosic sandstones. In a laboratory scale it was studied the possibility to obtain the feldspar concentrate and quartz sand from arkosic sandstones. Particle size distribution, chemical and mineralogical compositions of quartz-feldspar sands were determined. The bench-scale tests using the KOALIN AD laboratory experimental facilities were conducted. Many processing techniques were tested: disintegration, washing, sizing, carbonate flotation and feldspar flotation. The experimental results show that there are possibilities to obtain the silica sand with low content of Fe2O3 - below 0.02 % and potassium feldspar with content of K2O > 14 %. A new technology for recovery of feldspar and silica sand from arkosic sandstone was developed.

Ignatova T.,Kaolin AD | Mincheva K.,Kaolin AD | Ignatov S.,Kaolin AD | Dzhelyaydinova A.,Kaolin AD | And 2 more authors.
Journal of Chemical Technology and Metallurgy | Year: 2013

Worldwide, coarse dispersed kaolins are produced as a major fraction from processing of the primary kaolins. In this aspect, the superfine structure of the kaolins, production of "Kaolin" AD, due to their sediment (secondary) origin, is a problem. To date, the company has produced coarse dispersed kaolin, B0 sanitary grade by high energyintensive separating centrifuges, type "Humboldt". The aim of this paper is to study the possibility of obtaining coarse dispersed kaolin for ceramics using a new, lower-energy method - hydrocycloning. For this purpose, a 10 mm hydrocyclone of "Mozley-Natco" company in two configurations: overflow nozzle diameter (3.2 mm), an underflow nozzle diameter (2.2 mm), and overflow nozzle diameter (2.3 mm), underflow nozzle diameter (2.7 mm) was used. The lower hydrocycloning products in both configurations in terms of particle size and chemical composition are analogues of kaolin B0 sanitary, the coarse product of the separating centrifuge "Humboldt". The upper hydrocyclong product in the second configuration in terms of particle size and chemical content, respectively, is a complete analogue of kaolin FDK, the fine product of the separating centrifuge "Humboldt", while the hydrocyclone overflow in the first configuration is a new product for the company - kaolin FDK80, intended for paper coating.

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