VALORIZATION OF THE PYRITE IN VIEW OF THE SYNTHESIS OF FERRATE OF POTASSIUM

Synthesis of the alkali ferrate and the ferric sulphate

 It has been achieved in the laboratory of the Polytechnic Higher school of Antananarivo and the National Center of Industrial and Technology Research located at Antananarivo. Also, the various materials used for the realization of this work are : − the laboratory glasswares such as breaker, filters, vial, test glass, funnel,… − an oven that resists the basis attack, steady and adjustable and that one can use to a temperature until 1000 °C or more. − crucibles in stainless steel resists to the actions of the bases to high temperature ; The characterization of ore has been achieved in the mineral laboratory of the OMNIS [Office of the National Mines and Strategic Industries] located at Antananarivo. 2.1.2. Application in the treatment of the drinking waters The tests of flocculation and the analyses of waters have been achieved in the laboratory of analysis of the waters of the JIRAMA located in Antananarivo. The materials used ares thus: − adjustable Jar-Test speed between 0 and 150tr/mn ; − glassware ; − siphon ; − chronometer ; − material of measure of the pH, iron and M.O. ; − turbidity-meter ; − agitator. 

Synthesis of the alkali ferrate and the ferric sulphate

Ore used in the setting of this work has been collected in the District of Mampikony, region of Sofia (to see card below), whose geographical coordinates are the following: − latitude 16°05 ‘ south, − longitude 47°38 ‘S East Ore has been extracted by hand with the shovel and the spade.After extraction, ore has been analyzed to determine its composition. Then, we proceeded to the preparation that consists of the sifting and the washing of the ore. The synthesis of the ferrate has been achieved by the dry way that permits to produce a solid ferrate with a good output and stable hermetically. (Delaude 1996 ; Ostrosi 2007 ;Maghraoui 2012 ; Abdellah 2012) We started the synthesis of the ferrate with the making of the iron oxide. The diagram of the process of synthesis of the iron oxide from the pyrites is the following one (André 1931) : Figure 4 : Diagram of the process of synthesis of the iron oxide Note: One notices on this diagram that the ferric sulphate is an intermediate product for the manufacture of the iron oxide. Then, we carried to high temperature the mixture ferric oxide/potassium hydroxide/nitrate of potassium. The ferric sulphate and the ferrate of potassium thus gotten have been analyzed and have been used for the tests of treatment of drinking waters (Aubertin and al 1996 ; Sharma 2002). Then, we compared the performance of these two products in relation to the one of the sulphate of alumina in physic and chemical, bacteriological features point of view then and to the level of the optimum dose.