COPPER MINING WASTE, A SOURCE OF OLIGOELEMENTS FOR AGRICULTURE PUBLISHEDBogdan BORCEAN Lecturer ing. Lucian BOTOŞ, PHD
The examined material is the mining waste resulted from the banatite mining exploitations in South -Western Romania – Sasca Montană – Moldova Nouă region. This waste material contains important amounts of microelements (manganese, cobalt, boron, molybdenum, copper, zinc and others) and macro-elements (phosphorus, calcium, magnesium, sulphur). At the moment, the material is deposited in waste dumps of thousands of tones. It results of this paper that this mining waste contains mainly compounds of silicon (31.89%) and calcium (13.13%), followed by iron (5.32%) and aluminium oxides (1.25%) and sulphur (1.42%). The content of oligoelements found in the samples analyzed by I.C.I.M. Bucharest varies as follows: Copper 0.08 -0.1%, magnesium 1.7 – 2.4%, molybdenum 0.004 – 0.005%, zinc 0.02 – 0.07% and others. The graded composition of the material in the mining waste is: gravel 10%, coarse gravel 25%. The researches regarding the use of this material in agriculture were carried out on the territory of Sasca Montană, a region where the average annual temperature is of 11.5 °C according to the Meteorological Station Oraviţa and the annual precipitations are of 680 mm. The area belongs to the moderate temperate continental climate of Banat sub-type with submediterranean nuances. The mining waste was analysed on two cultures, maize and triticale. The soil type is a stagnic preluvosoil, having a poor acid reaction of between 0 – 160 cm (pH-5.71), with a moderate humus reserve. The effect of using 1 tone mining waste under the conditions of a differentiated fertilization with N0P50K50, N60P50K50, N120P50K50 and N180P50K50 was studied for both crops. The average increase in crop registered for the fertilization levels due to the use of mining waste was of 30% for triticale and of 22% for maize grains. The nitrogen fertilizers were well used by both cultures, both on a mining waste basis, and on a basis without mining waste. The average triticale crop for the two cultivation variants increased with 44% for the variant fertilized with N60, with 87% for the variant fertilized with N120 and with 118% for the variant fertilized with N180, under the conditions of a uniform fertilization with P50K50 For maize the crop increase when fertilized with nitrogen was of 56% for the variant fertilized with N60, of 90% for the variant fertilized with N120 and of 121% for the variant fertilized with N180.. The fertilizers were better used on a base of mine waste, because of the calcium contained in the material which partially neutralized the soil acidity.
banatite mine waste, source of oligoelements for plants