Asghar Azizi
Department of Mining, Petroleum and Geophysics, Un iversity of Shahrood, Shahrood, 36199-95161, Iran
[ 1 ] - An investigation of the corrosive wear of steel balls in grinding of sulphide ores
Ball mills are common grinding equipment in mineral processing industries. Ball wear results from three mechanisms namely impact, abrasion and corrosion. Of these, the corrosion mechanism is the least investigated, due to its chemical-electrochemical nature. Therefore, the aims of this research were to investigate the grinding chemistry influence (slurry pH, solid percentage, water chemistry an...
[ 2 ] - Desulfurization of coal by HNO3 leaching: Optimization of influential factors using Box-Behnken design
Sulfur is one of the most significant impurities in coal, which reduces the quality of coal and also results in environmental pollution. This work was aimed to investigate the removal of sulfur from coal by the leaching method employing parameters expected to affect the removal rate such as acid concentration (10-30%), temperature (40-80 °C), and reaction time (40-100 min). A response surface m...
[ 3 ] - Influence of operating parameters on the Apatite flotation kinetics
AbstractThe purpose of this study was to investigate the controllable operating parameters influence, including pH, solid content, collector, co-collector, and depressant dose, and conditioning time, on apatite flotation kinetics. Four first order flotation kinetic models are tested on batch flotation time-recovery profiles. The results of batch flotation tests and the fitting of first-order ki...
[ 4 ] - WEAR RATE PREDICTION OF GRINDING MEDIA USING BPNN AND MLR MODELS IN GRINDING OF SULPHIDE ORES
Nowadays steel balls wear is a major problem in mineral processing industries and forms a significant part of the grinding cost. Different factors are effective on balls wear. It is needed to find models which are capable to estimate wear rate from these factors. In this paper a back propagation neural network (BPNN) and multiple linear regression (MLR) method have been used to predict wear rat...
[ 5 ] - MODELING AND OPTIMIZING THE CORROSIVE WEAR OF STEEL BALLS IN BALL GRINDING MILL
This paper was aimed to address the modeling and optimization of factors affecting the corrosive wear of low alloy and high carbon chromium steel balls. Response surface methodology, central composite design (CCD) was employed to assess the main and interactive effects of the parameters and also to model and minimize the corrosive wear of the steels. The second-order polynomial regression model...
[ 6 ] - بررسی کاهش گوگرد پیریتی و محتوای خاکستر ذغال سنگ با استفاده از فروشویی با اسید نیتریک
زغالسنگ یکی از مهمترین منابع تامین انرژی است که در تولید کک مورد استفاده قرار میگیرد، اما حضور ناخالصی‌های گوگرد و خاکستر در زغالسنگ، کیفیت آنرا تحت تاثیر قرار میدهد و همچنین موجب آلودگی محیطزیست میشود. از این رو در این تحقیق، کاهش محتوای گوگرد پیریتی و خاکستر از زغالسنگ با استفاده از روش فروشویی مورد بررسی قرار گرفتند. بررسیها نشان داد که از میان عوامل مختلف فروشویی، اسید نیتریک بیشتر...
[ 7 ] - Modeling and Environmental Risk Assessment of Eastern Alborz Coal Washing Plant
Mining operations and mineral-related industries are closely and directly related with the environment. The negative impacts of mining industry on the environment, known as environmental risks, must be controlled and managed in a way to minimize harmful and destructive effects. Environmental risk assessment studies are a suitable step to identify, analyze and rank the risk factors. In this stud...
[ 8 ] - Leaching of Lead and Zinc from a Low-Grade Oxide Ore in Citric Acid Media
Leaching of a low-grade lead and zinc oxide ore was studied by an organic reagent, citric acid. The quadratic mathematical models were developed for the relationship among the influential parameters and lead and zinc recoveries. Leaching rate was strongly affected by the interactive effects of factors. It was also found that the quadratic effects of stirring speed and linear<e...
[ 9 ] - برآورد احتمالاتی توزیع بار در واحدهای فرآوری مواد معدنی با روش زنجیره مارکف
در روش‌های مرسوم موازنه جرم، برای تعیین عیار فلز، درصد جامد و توزیع دانه‌بندی نمونه‌برداری در مسیرها (شاخه‌ها) انجام میشود و در نهایت خطاهای مربوط به آنها سرشکن میشود. در این روش‌ها، برای هر واحد فرآوری (تجهیزات کارخانه)، در خصوص مقدار بار و عیار یا محتوای فلز اطلاعات لحظه‌ای وجود ندارد. در این مقاله با بهره‌گیری از نظریه فرآیند‌های تصادفی، مقادیر ...