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Geochemistry of the Igdekoy-Doganlar Na-Ca borate deposit, Emet Province (western Anatolia, Turkey)

Koçak İsmail

Geological Quarterly

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2020

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Vol. 64, No. 3

807--817

EN

Borates at the Igdekoy-Doganlar locality were deposited in a Miocene lacustrine environment during periods of Paleogene to Early Quaternary volcanic activity. The mineral paragenesis consists of probertite – NaCaB5O7(OH)4 3H2O, ulexite - NaCa[B5O6(OH)6] · 5H2O, hydroboracite - CaMg[B3O4(OH)3]2 3H2O, colemanite - Ca[B3O4(OH)3] · H2O, halite, anhydrite, glauberite, smectite and illite. The major element, Ca, is higher in the lgdekoy-Doganlar deposits compared to the averages for andesite and the Earth's crust. Within the trace elements, notable enrichment is identified in Li, Se, As, Sb, Sr and Cs. Lithium and Se occur in sufficient concentrations to be considered as economically valuable by-products. B and Sr anomalies can be used as an important marker in the exploration for boron deposits. The Y/Ho ratio of the lgdekoy-Doganlar borates is close to chondritic values. The negative Ce anomaly in borates from the lgdekoy-Doganlar deposit suggests that deposition occurred under oxidative conditions. The Eu and Ce anomalies reflect a hydrothermal contribution of REE. Geochemical and geological data suggest that the lgdekoy-Doganlar borate deposits were formed in high-pH playa lakes that were discharged from volcanic and terrestrial environments under evaporative conditions due to the effect of arid-semi arid climate.

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Effect of heat treatment on breakage rate function of ulexite

Ipek H., Sahan H.

Physicochemical Problems of Mineral Processing

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2013

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Vol. 49, iss. 2

651--658

EN

The kinetics of batch grinding and heat treated of ulexite using different size fractions (–3350+2360, –2360+1700, –1700+1180, 1180+850, –850+600, –600+425, –425+300, –300+212 and – 212+150 micrometers was determined using a standard Bond ball mill. It was found that breakage of ulexite follows the first order behavior for all feed sizes with the correlation coefficients equal to approximately 98%. The dry grinding of the single-sized fraction and heat treatment of ulexite showed that heat treatment samples were ground much faster than the original ulexite samples.

3

Investigation of structural chemistry of thermal processes applied for improvement of grindability of ulexite.

Sener S., Ozbayoglu G.

Physicochemical Problems of Mineral Processing

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2000

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Vol. 34

25-33

EN

In this investigation, mechanism of the thermal processes and effect of the mineralogical and structural modifications on the grindability of ulexite were investigated. The mechanism of the thermal reactions were examined by thermo-anal. methods including TGA and DTA. The mineralogical and structural modifications were investigated by XRD and SEM techniques, respectively. The results indicated that ulexite thermally decomposes within 60-500°C. The structure was first transformed into NaCaB5O6(OH)6.3H2O and then NaCaB5O decomposes 6(OH)6.H2O and finally became as completely X-ray amorphous phase accompanied with the thermal processes in the sequence of two-stage dehydration and two-stage dehydroxylation reactions resulting in two endothermic DTA peaks at 151°C and 180°C. Further treatment caused two-stage recrystallization. processes resulting in an exothermic DTA peak at 636°C and an endothermic peak at 855°C. The changes in the grindability of ulexite were determined. in terms of work index by the Hardgrove Grindability Test. The results showed that work index of ulexite was found as 7.11kWh/shton and decreased to 3.5 kWh/shton level within 200-280°C for 60 min. Further heating lead to 8.49 kWh/shton at 640°C for 60 minutes.

PL

W pracy badano mechanizmy procesów termicznych i wpływ przemian mineralogicznych i strukturalnych na rozdrobialność ulexytu. Badania mechnanizmów reakcji prowadzono metodą analizy termicznej w tym TGA i DTA, a zmiany mineralogiczne i struktutralne.za pomocą technik XRD i SEM. Wyniki wskazują, że ulexyt ulega termicznemu rozkładowi w zakresie 60-500 st.C. Najpierw powstaje NaCaB5O6(OH)6*3H2O a potem NaCaB3O6(OH)6*H2O) ostatecznie stając się amorficzny. Towarzyszą temu procesy termiczne, kolejno, dwustopniowe odwodnienie i dwustopniowa dehydroksylacja powodując dwa endotermiczne piki na krzywej DTA przy 151 st. C i 180 st.C. Dalsze ogrzewanie powoduje dwustopniową rekrystalizację powodując egzotermiczny pik przy 636 st. C. oraz endotermiczny pik przy 855 st. C. Zmiany rozdrabialności ulexytu określono za pomocą test rozdrabialności Hardgrove'a. Stwierdzono, ze indeks rozdrabialnosci ulexytu wynosi 7,11 KWh/krotka tonę i maleje do 3,5 KWH/krótką tonę dla probek wygrzewanych w zakresie 200-280 st. C. Przez 60 minut. Dalsze ogrzewanie w temp. 640 st.C przez 60 minut podnosi wartość indeksu do wartości 8,49 KWh/krótką tonę.