Pyrite Cinder Research Articles

Utilization of High Sulfur Raw Materials in Iron Ore Pellets

Pyrite cinder and high sulfur magnetite were used as raw materials to produce iron ore pellets. Good qualities of green balls and fired pellets were obtained from the feed comprising 50% pyrite cinder and 50% high sulfur magnetite concentrate at a small scale. Small-scale tests were proven by pilot-scale tests. The high grade fired pellets, assaying 63.22% Fe, were analyzed, and the compressive strength of fired pellets was over 2500 N/pellet. The fired pellets possessed excellent metallurgical performances, such as reducibility index higher than 67%, reduction swelling index lower than 15% and low temperature reduction degradation index (+ 3.15 mm) higher than 1%, which can be used as the burden for blast furnace.

Iron Oxide Red Pigment Prepared from Pyrite Cinders

Iron Oxide Red Pigment Prepared from Pyrite Cinders

Study on the Removal of Arsenic in Pyrite Cinder by Acid Leaching

For effective utilization of sulfate slag, the content of iron (Fe) should higher than 60%, while the content of asenic (As) should lower than 0.05%. A sulfate slag pretreated by magnetic separation-gravity separation, contains Fe 58.61% and As 0.33%, and the forms of Fe and As are mainly Fe2O3 and FeAsO4. To obtain qualified Fe ore concentrate product, chemical leaching conditions was used to remove As. Results show that the the optimal conditions are-0.074mm 75% grinding fineness, 30 °C, 15 g/L initial acid, 5/1 liquid-solid ratio, 350 rpm mixing intensity and 60 min leaching time. The obtained qualified product contains Fe 61.85%, As 0.045%, and Fe recovery rate is 98.63%.

Preparation of oxidised pellets using pyrite cinders as raw material

Pyrite cinders are a solid waste generated by the sulphuric acid industry and are considered environmentally hazardous. In order to try and recycle this material as a source of Fe units, the effects of different ratios of pyrite cinders to magnetite concentrate on the qualities of green and roasted pellets were evaluated. The results show that sulphur mainly exists as elementary sulphur in pyrite cinders and was nearly removed at the preheating stage. The higher the pyrite cinder content, the greater the porosity of the roasted pellets, leading to low compressive strength of the roasted pellets. Roasted pellets with acceptable quality for industrial use were obtained under the conditions of 40% pyrite cinders and 60% magnetite concentrate, preheating at 1000°C for 15 min and roasting at 1300°C for 15 min.

Heterogenous Fenton-Like Oxidation of Reactive Black 5 in Water Using Pyrite Cinder

As the Fenton-like oxidation reaction based on iron-bearing minerals could solve some problems of the traditional Fenton oxidation reaction, it became a talking point in academic circles worldwide recently. For the Fenton-like reaction, catalyst selection is an important research parameter. The new Fenton-like reaction uses iron-bearing cinder as catalyst by employing Reactive Black 5 (RB5), the object of investigation, as the target pollutant. By examining the dosage of catalyst, hydrogen peroxide, initial pH, reaction time, concentration of pollutants, optimized reaction conditions can be obtained. Results show that pyrite cinder gives rise to high catalytic activity in the Fenton-like reaction. When 5ml/L of hydrogen peroxide and 10g/L of cinder were added to 75mg/L of dye, the removal rate of RB5 was found to be 96% in 4 hours. Compared to the traditional Fenton reaction, it has a wider pH range and higher catalytic oxidation activity, especially under alkaline condition.

Process Optimization and Reaction Mechanism of Removing Copper From an Fe-Rich Pyrite Cinder Using Chlorination Roasting

The aim is to remove copper from a pyrite cinder by optimizing the chlorination roasting process using response surface methodology (RSM) and the reaction mechanism of chlorination roasting based on thermodynamic calculation was discussed. A quadratic model was suggested by RSM to correlate the key parameters, namely, dosage of chlorinating agent, roasting temperature and roasting time to the copper volatilization ratio. The results indicate that the model is well consistent with the experimental data at a correlation coefficient (R2) of 0.95, and the dosage of chlorinating agent and roasting temperature both have significant effects on the copper volatilization ratio. However, a roasting temperature exceeding 1170°C decreases the volatilization ratio. The optimum conditions for removing copper from the cinder were identified as chlorinating agent dosage at 5%, roasting temperature at 1155.10 °C and roasting time of 10 min; under such a condition, a copper volatilization ratio of 95. 16% was achieved from the cinder. Thermodynamic calculation shows that SiO2 in the pellet plays a key role in the chlorine release from calcium chloride, and the chlorine release reactions cannot occur without it.

Treatment of Pyrite Cinders for Arsenic Removal Using Acid Leaching Process

A craft of concentrated acid-heating reinforced leaching process is investigated for the treatment of a high arsenic pyrite cinder, a common by-product in vitriol industry. The pyrite cinder, containing 57.37% Fe, and 2.78% As, was conducted for the acid leaching process. The results demonstrated that iron concentrate with 60.57% Fe, 0.28% As and 96.23% of iron recovery was obtained under the optimal acid leaching conditions(Sulphuric acid concentration is a mass ratio of 20%, a leaching temperature of 60°C, a liquid-solid ratio of 2:1 and a leaching time of 120 min).This craft can be used to utilize pyrite cinder and produce qualified concentrate as iron-bearing feed for steel industry, which will help to solve the pollution of sulfuric acid residue and extend raw material sourcing for Chinese steel industry.

Research on Balling Properties of Pyrite Cinder with High Content of Copper

The balling properties of pyrite cinder (PyC) with high content of copper are researched in this paper. The results indicate that grinding process is an effective way to improve the quality of green balls. Through the measuring of drop strength compressive strength and cracking temperature on pyrite cinder balls, it is found that the best bailing properties of PyC can be obtained under the recommended parameters (the content of grain size of PyC below 75 μm accounts to 95.75% and bentonite dosage is a mass ratio of 2%) and green balls with 5.4 frequency•(0.5m)-1 of drop strength, 15.8 N•each-1 of compressive strength and cracking temperature of about 700 °C are obtained, which can meet the requirements of metallurgical technology.

Leaching and Kinetic Modeling of Pyrite Cinder in Sulphuric Acid

Leaching and Kinetic Modeling of Pyrite Cinder in Sulphuric Acid

Research on Process Mineralogy of some Pyrite Cinder

The characteristics of process mineralogy of some pyrite cinders were studied with optics microscopes, scanning electron microscope, and x-ray diffraction. The chemical composition and the phase composition of the pyrite cinders were analyzed. The occurrence and chemical phase analysis of molybdenum of iron, copper, and gold were also studied. The behaviors of various minerals and mineralogical factors affecting the separation had been explained clearly. The investigation results were favorable to reasonable selection of technological process.

Efficiently Produce Iron Concentrate from High-Purity Pyrite

The study attempts to produce iron concentrate from a high-purity pyrite concentrate using oxidizing roasting at industry scale. The effect of key parameters, i.e., roasting temperature, excess air coefficient and roasting intensity on the Fe and S content in the pyrite cinder was fully investigated. The results indicate that the roasting temperature plays a key role in decrease the S content in the pyrite cinder; an increase in the roasting temperature from 800°C to 950°C decreased the S content in the pyrite cinder remarkably from 0.43% to 0.18%. The optimum conditions for produce a high quality iron concentrate from the high-purity pyrite concentrate were identified as roasting temperature around 900 ~ 950°C, excess air coefficient at 1.20 and roasting intensity at 4.36 ~ 5.61 t / m2•day. Under such a condition, high-quality iron concentrate containing 65.11% Fe and 0.21% S was achieved from the pyrite concentrate.

Response Surface Design for Remove of Copper from a Fe-Rich Pyrite Cinder

The study aims to remove copper from a pyrite cinders using chlorination roasting and optimizing the roasting parameters through response surface methodology (RSM). After a series of experiments, a quadratic model was suggested by RSM to correlate the variables to the copper volatilization ratio. The results indicate that the model is in good agreement with the experimental data and the dosage of chlorinating agent and roasting temperature play a key role in improving the volatilization ratio. The optimum conditions for remove copper from the cinders were identified as chlorinating agent dosage at 5%, roasting temperature at 1155.05 °C and roasting time of 10 minutes; under such a condition, an average copper volatilization ratio of 95.16% was achieved from the cinder.

The Progress of the Preparation of Coagulant from Industrial Wastes

An overview of characteristics and existence status of industrial wastes such as fly ash, coal gangue, red mud and pyrite cinder. The research progress of the preparation of wastewater treatment coagulants from industrial wastes has been introduced in detail. And some existing problems of the preparation of coagulants from industrial wastes have been pointed out, the solutions have been put forward.

Technology and Mechanism of Valuable Metal Recovery from Pyrite Cinder by Chloridizing Roasting

A new technology of pellet production-drying-chloridizing roasting is proposed for valuable metal recovery from pyrite cinder with high content of lead and zinc. The pyrite cinder, containing 60.15% Fe, 2.02% Pb and 2.15% Zn, was pelletized with addition of 2% bentonite in pan pelletizer. Green balls after drying were roasting at 1100 °C for 60 min with 5 wt % of CaCl2 addition in tube furnace. The results demonstrate that pellets with 61.58% of TFe, lead and zinc volatile ratios of 98.02% and 96.83% were obtained. Key technique is that CaCl2 reacts with lead and zinc compounds and the chloride can be volatilized at moderate temperatures. This new technology can recover the valuable metal fully from pyrite cinder and produce qualified concentrate as iron-bearing feed for steel industry, which will help to solve the pollution of pyrite cinder and extend raw material sourcing for Chinese steel industry.

Effect of Pyrite Cinder on Calla Lily Antioxidation

The effect of pyrite cinder on calla lily antioxidation was researched by solution culture method.The experimental result shows that compared with the control,using pyrite cinder can obviously increase plant chlorophyll content and promote the photosynthesis of calla lily.Along with treating time prolonging, SOD,CAT,POD and MDA contents all show ascending first and then descending,and they are all higher than plants that have not used pyrite cinder.It presents that pyrite cinder has strong influence on calla lily growth,and can promote plant growth.

Reduction mechanisms of pyrite cinder-carbon composite pellets

The non-isothermal reduction mechanisms of pyrite cinder-carbon composite pellets were studied at laboratory scale under argon (Ar) atmosphere. The composite pellets as well as the specimens of separate layers containing pyrite cinder and coal were tested. The degree of reduction was measured by mass loss. The microstructures of the reduced composite pellets were characterized by scanning electron microscopy (SEM). It is found that the reduction processes of the composite pellets may be divided into four stages: reduction via CO and H2 from volatiles in coal at 673–973 K, reduction via H2 and C produced by cracking of hydrocarbon at 973–1123 K, direct reduction by carbon via gaseous intermediates at 1123–1323 K, and direct reduction by carbon at above 1323 K. Corresponding to the four stages, the apparent activation energies (E) for the reduction of the composite pellets are 86.26, 78.54, 72.01, and 203.65 kJ·mol−1, respectively.

Utilization of phosphate fertilizer industry waste for belite–ferroaluminate cement production

Phosphogypsum (PG) and pyrite cinder (PC) are phosphate fertilizer industry wastes. At present, the utilization of PG and PC is limited, their stockpiling brings about serious environmental problems. We studied the manufacturing technique for producing belite–ferroaluminate cement utilizing of PG and PC as raw materials instead of natural materials. The mechanical properties, mineral composition and microstructure of the resulting cement clinker were investigated using X-ray powder diffraction (XRD) with Rietveld quantitative phase analysis, scanning electron microscope (SEM), etc. We found that burning at 1250°C for 60min was suitable for clinker production. The effect of natural gypsum (NG) content on setting time, heat evolution, compressive strength, hydration products of cements were also investigated. The results show that setting time of cement depends much on NG content. The early hydration accelerates with NG content increasing. The effect of NG content on compressive strength at different curing age is variable. NG content in cement is also an important factor in the hydration products.

Response Surface Methodology for Optimization of the Chloridizing Roasting Process for a High Copper Pyrite Cinder

This study aimed to obtain volatile copper from a high-copper pyrite cinder by optimizing the chloridizing roasting process using response surface methodology (RSM). The effect of key parameters, i.e., dosage of CaCl2 addition, roasting time and roasting temperature, on the copper volatile ratio was investigated and a quadratic model was suggested by the methodology to correlate the variables to this volatile ratio. The results indicated that the model was in good agreement with the experimental data at a correlation coefficient (R2) of 0.9782, and the most influential parameter on efficiency was identified as the dosage of CaCl2 addition. The optimum conditions for chloridizing roasting from the high copper pyrite cinder were identified as a dosage of CaCl2 addition of 4.8 wt%, a roasting time of 19.28 min and a roasting temperature of 1151.51 °C; under such conditions, a copper volatile ratio of 97.82% was achieved. The pellets obtained by this process are characterized by a high content of hematite, and the main impurity element contents are consistent with the requirements for iron concentrate, which is suitable for use in ironmaking.

A New Kind of Catalyst for Enhancing the Conversion Rate of Fe<sup>2+</sup> to Fe<sup>3+</sup>

In poly ferric sulfate production process with pyrite cinder as the main raw material, the sodium nitrite as catalyst is too toxic to be used largely. By orthogonal experiment and single factor experiments, the best reaction conditions were studied for the sodium nitrite as the catalyst, the amount of catalyst is 0.8%, the reaction temperature is 50°C and the reaction time is 60 minutes. According these conditions, the catalyst (CH-2) was used to promote the oxidation-polymerization reaction. Results showed that the use of this non-sodium nitrite catalyst could not eliminate the product toxicity that would be caused by using sodium nitrite catalyst but also make the toxicity of PFS was eliminated and the performance was better.

‘One step’ technology to separate copper, zinc, lead from iron in metallurgical slag and pyrite cinder Part 1 – Laboratory scale test

In this paper, a study of processing pyrite cinder and metallurgical slag using a ‘one step’ technology in strand grate–rotary kiln at a laboratory scale is presented, which aims to recover iron, lead, zinc and copper. The compressive strength of preheated pellets reached 527 N per pellet and the removal rates of copper, lead and zinc reached 36·36, 92·86 and 20·0% respectively, when the green balls were preheated at 1125°C for 10 min. Reduction of preheated pellets was followed, at the carbon/iron ratio of 3·0 and 1100°C, for the reduction time of 70 min, and the metallisation degree of 86·31%, the compressive strength of 1777 N per pellet and the copper, lead and zinc removal rates of 36·36, 99·12 and 71·00% were achieved respectively. These prereduced pellets with 80·58%Fe made from pyrite cinder and metallurgical slag can be widely applied to enhance the operation of blast furnace.