The causes of extra high grade presented in rock gold deposit are briefly introduced in this paper,and a new method of calculating the average grade of ore deposit is discussed when optimizing the grade index of rock gold deposit.
Through study on ultra high grade and regularity of minerogenetic enrichment of Hetai Gold Deposits,the influence of ultra high grade on the problem such as negative variation of the grade which exists all over gold mines is pointed out . It is also found that separately defining rich pocket in the enrichment zone of valued components has important effect to raise the grade of processing ore and economic benefit of mine.
When the curves of the grade of sample and frequency show the asymmetric normal distribution, through the mathematical statistics of the sample grade and by using calculation of the normal distribution intergral function, we can determine the samples whether belong to super high grade.
In India, heavy machine tools, locomotives, automobiles, aviation, ship building and engineering tools require super grade steels with various specifications and these are met by mini iron and steel industrial plants.