UDC 669. 054:669.849 Results are provided for thermal and thermogravimetric studies of lead sludge in the presence of and without oxidizing agents in order to determine the thermally active part of the charge composition. It is shown that during oxidation firing of lead sludge the process begins with charge dewatering and organic compound decomposition, and rare metal oxidation commences after complete destruction of organic compounds. Addition of sodium nitrate or calcium hypochlorite oxidizing agents provides complete oxidation of rhenium and osmium in the range of 400-650°C with the subsequent extraction of osmium into sublimate and concentration of rhenium in the form of perrhenate compounds in the ash. In this case decomposition of organic substances proceeds in parallel with oxidation reactions of rare metals without affecting their oxidation.
The article presents the results of oxidative leaching of lead sludge from copper production in order to extract rhenium into solution. The optimum regimes for product leaching man-made product in the presence of sodium peroxocarbonate Na2CO3·1.5H2O2 has been established: Experimental work was carried out under the following conditions: oxidant consumption 5% by weight of the raw material, leaching temperature 70°C, duration 30–60 minutes, stirring speed 200 rpm, and the ratio of liquid to solid S : L = 1 : 3. The degree of extraction of rhenium into the solution is 95–97%, and the content reaches 500–520 mg/L Re.
The process of oxidative firing of lead sludge in the presence of calcium hypochlorite was studied in order to convert rhenium compounds to calcium perrenate. The optimal conditions for the firing process are found: the firing temperature is 500-600°C, the firing duration is 30-60 minutes, the oxidizer consumption is 20-40 % of the sludge mass. The influence of the stub leaching conditions on the degree of rhenium extraction into the solution was studied. Under the found optimal conditions, the degree of rhenium extraction into the solution was 93-94 %.
This article studies the oxidative firing process of lead sludge of copper production for the purpose of extracting rhenium. As an oxidizer, calcium hypochlorite is used, which is simultaneously an oxidizer of low-valent rhenium compounds and a binding reagent of rhenium oxides to calcium perrenate. Optimal conditions for the firing process are found: the firing temperature is 500-600°C, the firing duration is 30-60 minutes, and the oxidizer consumption is 20-40 % of the sludge mass. As a result of thermal studies and experimental work, it was established that the rhenium oxidation process begins at 180-260 °C after the decomposition of calcium hypochlorite and completely ends at 500-600 °C with the formation of calcium perrenate. During water leaching of the stub under the following conditions: T: W=1: 3, temperature of 70 °C, duration of 60 minutes, a solution containing 546 mg/l of rhenium was obtained. The degree of rhenium recovery in the solution was 93-94 %.
Национальный центр по комплексной переработке минерального сырья Республики Казахстан (НЦ КПМС РК), г. Алматы Статья поступила в редакцию 05.05.16 г., доработана 01.08.16 г., подписана в печать 18.08.16 г. Изготовлен укрупненный вариант флотоаппарата с высоконапорным ротационным пульсационным аэратором (ВРПА). Проведены исследования и испытания на труднообогатимой тонковкрапленной золотосодержащей пробе руды одного из месторождений Казахстана. Эксперимент и практика флотации с разработанным авторами ВРПА показали, что колебания давления, которые создаются аэратором, обеспечивают эффективность функционального использования двух периодов: (1) растворение дополнительного количества газов в высоконапорном периоде сжатия, что обеспечивает процесс аэрации необходимым количеством растворенных газов; (2) псевдокавитационное выделение газов в периоде разрежения среды, чем и обеспечивается аэрация с выделением газов из водной фазы непосредственно на гидрофобных минеральных микрочастицах, т.е. селективная флотация микродисперсий. Полученные результаты показали, что при флотации руды на флотоаппарате с ВРПА получен весьма существенный положительный эффект не только по извлечению металлов, но и по качеству получаемых концентратов. Ключевые слова: пульсационный флотоаппарат, колебания, аэратор, высоконапорное сжатие, псевдокавитация, вещественный состав, показатели испытаний. Жарменов А.А. -докт. техн. наук, акад. НАН РК, ген. директор НЦ КПМС РК (050036, Республика Казахстан, г. Алматы, ул. Жандосова, 67).
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