سیدضیاالدین شفائی تنکابنی
استاد فراوری مواد معدنی، دانشگاه تهران
[ 1 ] - جداسازی کالکوسیت از پیریت به روش فلوتاسیون با کنترل پتانسیل الکتروشیمیایی پالپ
در این تحقیق اثر کنترل پتانسیل الکتروشیمیایی پالپ (Eh) بر روی جدایش کالکوسیت از پیریت در حضور اتیل‌گزنتات پتاسیم در pHهای مختلف مورد بررسی قرار گرفته است. نتایج نشان داده است که جدایش این دو کانی شدیداً وابسته به پتانسیل الکتروشیمیایی و pH پالپ می‌باشد. در صورتی‌که بدون کنترل پتانسیل پالپ (در پتانسیل‌های آزاد پالپ)، وتنها با تنظیم pH، جدایش موثری حاصل نمی‌شود. بیشترین جدایش در 11=pH و در محدوده ...
[ 2 ] - مدل‌سازی تحلیلی از فرآیند بیولیچینگ تودهای (فروشویی زیستی)
در این مقاله، شبیهسازی فرآیند لیچینگ باکتریایی تودهای و ارزیابی تحلیلی فرآیندهای درگیر در شرایط ناپایا از طریق مدلهای تحلیلی برای کانسنگ کمعیار مس بسط و گسترش داده شده است. المان انتگرالی تعریف شده عبارت است از واحد حجم توده که شامل فاز جامد (با توزیع اندازه ذرات کانسنگ)، فاز مایع (محلول شسته شده ساکن و جاری حاوی مواد حلشده و باکتریهای چسبیده و معلق) و فاز گاز (جریان هوا و حبابه...
[ 3 ] - ارزیابی چیدمان مدارهای فلوتاسیون با تلفیق روش تحلیل مدار‌خطی و نمودار جریان سیگنال، درکارخانه مس قلعه زری
در مدارهای فرآوری مواد معدنی، از جدایش مرحله‌ای برای تولید محصولی با بازیابی و کیفیت مناسب استفاده می‌شود. چون به‌طور معمول، سالانه میلیون‌ها تن ماده معدنی در این مدارها تحت عملیات پرعیارسازی قرار می‌گیرد، دستیابی به بهبودی اندک از طریق تغییر در چیدمان مدار می‌تواند تاثیر اقتصادی قابل‌توجهی داشته باشد. همچنین چون برای یک مدار جدایش، طرح‌های مختلفی وجود دارد یافتن بهترین...
[ 4 ] - بررسی رفتار شناور سازی کالکوپیریت در حضور سولفیدسدیم با کنترل پتانسیل
.در این تحقیق، رفتار شناورسازی کالکوپیریت بصورت تک‌کانی و ترکیبی (کنسانتره کالکوپیریت) در حضور مقادیر مختلف سولفیدسدیم در سه سطح pH (7، 9 و 12) تحت کنترل پتانسیل الکتروشیمیایی پالپ مورد بررسی قرار گرفت. از روش اسپکتروسکوپی فتوالکترون اشعه ایکس (XPS) بعنوان یک روش توانمند آنالیز سطح برای شناسایی ترکیبات سطحی هیدروفیل و هیدروفوب به منظور تحلیل مکانیزم شناورسازی و بازداشت کالکوپیریت در شرایط مختلف...
[ 5 ] - بررسی بازیابی روی موجود در سد باطله معدن سرب و روی کوشک به روش ژئوکوت
در این تحقیق امکان استخراج روی ازکنسانتره کم¬عیار تهیه شده از باطله¬های سولفیدی فلوتاسیون معدن سرب و روی کوشک با استفاده از روش بیولیچینگ ژئوکوت مورد بررسی قرار گرفت. باطله¬های تهیه شده از سد باطله، با عیار متوسط روی 67/3% ، به سلول¬های فلوتاسیون انتقال و کنسانتره¬ای با عیار روی 97/11% و بازیابی متوسط 45% تهیه شد. کنسانتره حاصل بر روی سنگ¬های گرانیتی با محمدوده دانه¬بندی10-5 میلیمتر پوشش داده ش...
[ 6 ] - تعیین عیار ماده معدنی با استفاده از شبکه عصبی MLP و تکنیک پردازش تصویر
در این مقاله امکان تعیین عیار مواد معدنی با استفاده از شبکه عصبی و تکنیک پردازش تصویر مورد بررسی قرار گرفت. نمونه‌های مورد استفاده دراین طرح از معدن چغارت یزد تهیه و تعداد آنها نیز 100 عدد بوده است. در این طرح با تهیه عکس از نمونه‌های پودر شده با دوربین عکاسی دیجیتالی حرفه‌ای و با استفاده از ویژگی‌های تصویری عکس‌ها شامل سه رنگ اصلی قرمز، آبی و سبز(RGB) تصاویر و ویژگی بافتی‌هارلیک شامل انرژی[i] ...
[ 7 ] - Mixed moderate thermophilic bioleaching of Cu, Mo and Re from molybdenite concentrate: effects of silver ion, medium and energy sources
This study evaluates the effects of different additives such as silver ion, medium and energy sources on the efficiency of mixed moderate thermophilic bioleaching approach to extract Cu, Mo and Re from molybdenite concentrate containing 0.98% Cu, 1.56% Fe, 53.84% Mo, and 0.055% Re. Molybdenite was the major phase of Mo-bearing mineral and chalcopyrite, covellite and pyrite were distinguished as...
[ 8 ] - The role of catalyst in the passivation of chalcopyrite during leaching
In this work, we present as investigation of chalcopyrite leaching under different leach conditions for how liquidation and surface of chalcopyrite study using Scanning Electron Microscopy (SEM) to determine the composition of the passivation layer in the surface of chalcopyrite. The study of chalcopyrite dissolution were in H2SO4 solution systems at pH of 1.2, with 5% chalcopyrite concentrate ...
[ 9 ] - Kinetics of chalcopyrite galvanic leaching using sulfate media at the low temperature in the GalvanoxTM process
In this research work, the dissolution of chalcopyrite was investigated under atmospheric pressure, with sulfate media at low temperatures, in 30°C to 50°C. In the galvanic interaction between chalcopyrite and pyrite, pyrite is used as a leaching catalyst. Effects of different parameters such as temperature, stirring speed, pyrite to chalcopyrite ratio, particle size, and solution potential wer...
[ 10 ] - Bioleaching of a low grade sphalerite concentrate produced from flotation tailings
In this research work, the zinc extraction was investigated, using bioleaching process from a low grade zinc concentrate which was produced from the accumulated flotation tailings. Zinc content was initially upgraded to 11.97% by flotation process. Bioleaching experiments were designed and carried out by a mixed culture of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospir...
[ 11 ] - Application of gravity separators for enrichment of South Chah-Palang tungsten ore
In the present study, the possibility of concentrating tungsten-copper vein ore in South Chah-Palang was examined using gravity separators including Jig Machine (-2360+600 μm), shaking table (-600+120 μm), and multi-gravity separator (MGS) (-120 μm). The representative sample contains 1.5% WO3 and 5.95% CuO. The main tungsten minerals were ferberite and wolframite and their appropriate liberati...
[ 12 ] - 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...
[ 13 ] - The Effects of Ore Properties on the Characterization of Suspension in Settling and Compression
Many studies have considered the effects of suspension properties on the dewatering process but fewhave focused on ore properties. Thus, the present work studied the effects of ore properties (density,particle size, mineralogy) on the dewatering process based on lab and pilot experiments. A hydrocyclonewas used to prepare the required samples for the experiments. To study the effects of mineral...
[ 14 ] - The Effect of Different Additives and Medium on the Bioleaching of Molybdenite for Cu and Mo Extraction Using Mix Mesophilic Microorganism
Bioleaching processes for extraction of Cu and Mo from molybdenite cons. are more environmentally friendly and consume less energy than conventional technologies, yet less economically efficient. One necessary step towards arriving at a cost-effective bioleaching process is using appropriate methodology to optimize pertinent factors in such processes. To this end, the present study employed Res...
[ 15 ] - A comparative study of two-stage flotation of Zn and Pb oxide minerals using anionic, cationic, and mixed (cationic/anionic) collectors
A lead-zinc carbonate ore sample containing 2.5% Pb and 9.39% Zn was used in this research work. The sample was prepared from the Darreh-Zanjir mine located in the Yazd province (Iran). Influences of the influential factors on flotation of smithsonite and cerussite were investigated. Among the different parameters involved, dosages of the dispersant, depressants, sulfidizing agent, and collecto...
[ 16 ] - Effect of frother type and operational parameters on nano bubble flotation of quartz coarse particles
In this work, the effects of the types of frother (MIBC, pine oil, and A65) and operational parameters (impeller speed and air flow rate) on the flotation of quartz coarse particles was investigated using nano bubbles (NBs). Quartz particles of the size of -425+106 mm and three types of frother were used for the flotation experiments. Also the impeller speed was 600 to 1300 rpm, and the air flo...
[ 17 ] - Optimization of parameters affecting recovery of copper from Sarcheshmeh low-grade sulfide ore using Bioleaching
In this work, the parameters affecting the recovery of copper from the low-grade sulfide minerals of Sarcheshmeh Copper Mine were studied. A low-grade sulfide ore was used with a copper grade of 0.25%, which was about 28% of the mineral oxide, and the sulfide minerals made up the rest. Much more sulfide minerals were found to be pyrite and most of the gangue minerals were quartz, anorthite, bio...
[ 18 ] - Investigation of performances of solvents D2EHPA, Cyanex272, and their mixture system in separation of some rare earth elements from a Nitric Acid solution
This work was aimed to evaluate and compare the performances of the solvents D2EHPA (Di-(2-ethylhexyl) phosphoric acid), Cyanex 272 (bis (2,4,4-trimethylpentyl) phosphinic acid), and a mixture system of D2EHPA and Cyanex272 in the separation of some rare earth elements (REEs) including lanthanum, gadolinium, neodymium, and dyspersym from a nitric acid solution. The results obtained showed that ...
[ 19 ] - Effect of grinding time on flotation recovery of copper smelting slags in Bardaskan district
Copper smelting slags are hard materials. Therefore,to recover their copper by flotation method, grinding should be carried out to obtain optimal particle size. Copper smelting slags in the Bardeskan district, with work index of 16.24 kwh/st, were grinded for 65 minutes to reach an acceptable degree of freedom for the flotation tests, with particle size of 80%, smaller than 70 μm. With this gri...
[ 20 ] - Optimization of cyanidation parameters to increase the capacity of Aghdarre gold mill
This study investigates the optimization of gold dissolution from Aghdarre ore. Therefore, a laboratory investigation was initiated, to improve the leaching conditions with the objective of maximizing mill capacity with no reduction on gold recovery. It was observed that the time reduction from 25 to 15 hours did not change the gold recovery. In the other words, it indicated that a capacity of ...
[ 21 ] - Stage specialization for design and analysis of flotation circuits
This paper presents a new approach for flotation circuit design. Initially, it was proven numerically and analytically that in order to achieve the highest recovery in different circuit configurations, the best equipment must be placed at the beginning stage of the flotation circuits. The size of the entering particles and the types of streams including pulp and froth were considered as the bas...
[ 22 ] - Investigating the effects of particle size and dosage of talc nanoparticles as a novel solid collector in quartz flotation
In this study, hydrophobic talc nanoparticles were applied as a novel class of solid flotation collector. The aim of this work was to understand the effect of talc nanoparticles size and dosage on the quartz flotation recovery. X-ray analysis, dynamic light scattering, and scanning electron microscopy were conducted. Flotation tests were performed in modified a Hallimond flotation cell. The Zet...
[ 23 ] - Flotation of zinc silicate ore: A focus on effective parameters, synergistic effect of mixed cationic collectors and its mechanism
The present study addresses the direct flotation route for the concentration of a zinc silicate ore. Flotation of hemimorphite faces some challenges due to the similarity of hemimorphite and quartz surface properties. XRD, and XRF analyses, optical mineralogy and SEM with X-ray mapping were performed for characterization. The results showed that the quartz, hemimorphite, calcite and dolomite ar...
[ 24 ] - Recent developments in configuration design and optimization of mineral separation circuits; A Review
The present research reviews two basic approaches for the separation circuit configuration analysis. The first approach is to optimize the circuit configuration. In this method, after a circuit modeling, a variety of search algorithms and mathematical optimization methods are used. Previous works show that this approach has more application in the flotation process. The second approach called t...
[ 25 ] - The effect of chemical composition and burning temperature on pellet quality
The effect of pellet chemical composition and burning temperature on pellets’ properties of the Gol-e-Gohar hematite recovery plant was investigated in this study. Green pellets of different sodium hydroxide ratio and hydrated lime were prepared as well. Then the pellets were burnt in a muffle kiln under different temperature conditions. The Design Expert software was employed to explore ...
[ 26 ] - Enhancement of Phosphate Flotation by Ultrasonic Pretreatment
Removal of carbonate impurities in sedimentary phosphate is one of the most important issues in the industry. Poor selective flotation of those ores is due to the similarity of Physico-chemical surface properties, solubility and electrokinetic characteristics of sparingly soluble phosphate and carbonate minerals. In this study, the effect of ultrasonic irradiation as a pretreatment method o...
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