Dust Briquettes Research Articles

Metallurgical Properties of Vacuum Extrusion Iron‐Rich Dust Briquette and Its Effects on Blast Furnace Soft Melting Zone

The vacuum extrusion iron‐rich dust briquette (VEIDB) in this study is prepared by vacuum extrusion of iron ore fines and blast furnace dust. In this article, the metallurgical properties such as compressive strength, tumbler strength, low temperature reduction disintegration performance, reducibility, and softening melting properties of VEIDB are studied. The effect of VEIDB on the soft melting zone of blast furnace is also studied. Results show that the compressive strength of VEIDB is 5.684 kN/VEIDB, the tumbler strength is 89.87%, RDI−0.5 = 2.82%, and the metallization degree after reduction is 96.9%. However, its softening and melting properties is bad. The study on the influence of VEIDB on softening and melting properties of iron‐containing burden shows that, adding VEIDB in blast furnace burden would make the soft melting zone of blast furnace move up and expand; with the increase of the VEIDB amount, the permeability decreases first and then increases. The addition of VEIDB in blast furnace burden should be controlled within 10%.

Evolution behavior and kinetic analysis of vacuum-extruded iron-rich dust briquette in blast furnace

The vacuum extrusion iron-rich dust briquette was prepared by vacuum extrusion of iron ore concentrates, blast furnace dust and Portland cement. The evolution behavior and kinetic analysis of briquette in blast furnace was studied by high temperature process interrupted experiment. The phase transformation, metallurgical strength, microstructure and three-dimensional structure of dust briquette during high temperature reduction process were analyzed by X-ray diffraction, scanning electron microscope, energy dispersive spectroscopy and micro computed tomography. It is found that the high temperature reduction process of briquette can be divided into six stages, and the mechanical strength of briquettes under reducing atmosphere decreases with the increase of reduction degree and metallization rate, from 4.58 KN at 100 °C to 0.52 KN at 1100 °C. As the temperature increases, the metal iron and porosity inside briquette gradually increase. The ratio of the volume of metallic iron at 700 °C, 900 °C and 1100 °C was 1.47%, 3.70% and 6.60%, and the porosity is 10.32%, 34.1% and 47.1%, respectively. Furthermore, the non-isothermal kinetic reduction process of briquette was analyzed, and the evolution mechanism was revealed. The reduction process of briquettes is mainly controlled by diffusion, and only in the fourth stage (510 °C–840 °C) is limited by the reduction reaction of magnetite and decomposition reaction of calcium carbonate. This paper provides a theoretical support for the efficient and economical recycling of dust in iron and steel enterprises.

Manufacturing, curing and mechanical testing of BREX from electric arc furnace dust

At present the acute issue is utilization and recycling of metallurgical production wastes; one of which is electric arc steelmaking dust (EAF). In Russia there are up to 30 million tons of dust in the dumps of metallurgical plants and additionally up to 780 thousand tons are added to this amount annually. Considering the amount, the main value is zinc, which content reaches 25 wt%, as well as iron, which content varies from 20 to 50 wt%. The paper presents the results of studies on briquetting of the EAF dust using the technology of stiff extrusion and obtaining brackets. The chemical composition of the initial EAF dust was studied by X-ray spectral analysis using JEOL JSM-7001F electron microscope. The amount of reducing agent was selected based on results of thermodynamic modeling using the TERRA software package. The BREX were produced in a laboratory extruder assembled from an electric motor, a reduction gear, a screw, and a die. Two types of dies were used in the briquetting study. For each type the optimum moisture and binder were selected. The influence of the binder and moisture on the quality of the finished briquettes was evaluated. The BREX drying was studied in order to find out the optimum curing time in the air. In addition, drying at 110 °C was carried out for a comparative assessment of the strength of briquettes depending on the method of drying. The drop tests of the finished briquettes were carried out according to GOST 25471‒82 “Iron ores, sinter and pellets; method for determining dumping strength”. The test results showed the possibility of transportation of the EAF dust briquettes

Comparison of Compressive Strength of Fly Ash Bonded Flue Dust Briquettes with that of Briquettes made with Bentonite, Sodium Silicate, Lime, Starch, Pitch, Molasses and Dextrin Binder

Comparison of Compressive Strength of Fly Ash Bonded Flue Dust Briquettes with that of Briquettes made with Bentonite, Sodium Silicate, Lime, Starch, Pitch, Molasses and Dextrin Binder

Study of the effect of the composition of the binder on the mechanical characteristics of dust briquettes of electric arc furnace production

.

Study of the Influence of the Binder Composition on the Mechanical Characteristics of Dust Briquettes from Electric Arc Furnace Production

Study of the Influence of the Binder Composition on the Mechanical Characteristics of Dust Briquettes from Electric Arc Furnace Production

Performance evaluation of throat type updraft biomass gasifier using different biomass fuels

A biomass gasifier converts solid fuel such as wood waste, saw-dust briquettes and agro-residues into a gaseous fuel through a thermo-chemical process and the resultant gas can be used for thermal and power generation applications. The present research aims to evaluate the updraft biomass gasifier using different biomass for thermal application. The capacity of updraft gasifier was a 5-10 kg.h-1 and three types of biomass: maize cobs, sized wood and saw dust briquettes were used as fuel for producing producer gas by thermal application. The maximum carbon monoxide (CO), hydrogen (H2) and Methane (CH4) found were 14.8, 12.7 and 3.9%, 14.6, 13.7 and 3.9 % and 14.2, 13.5 and 3.9% at 5 kg.h-1 biomass consumption rate, respectively using maize cobs, sized wood and saw dust briquettes as fuel. The maximum and minimum producer gas calorific value was found 1120 and 1034 kcal.m-3; 1139 and 1034 kcal.m-3 and 1123 and 1036 kcal.m-3 at biomass consumption rate of 5 and 10 kg.h-1 using maize cobs, sized wood and saw dust briquettes as fuel respectively. The maximum gasifier efficiency of 77.94, 70.26 and 69.60% was found at the biomass consumption rate of 5 kg.h-1 using maize cobs, sized wood and saw dust briquettes as fuel, respectively. The minimum gasifier efficiency of 72.72, 64.49 and 64.90 % was found at the biomass consumption rate of 10 kg.h-1 using maize cobs, sized wood and saw dust briquettes as fuel in the system, respectively. The maximum overall thermal efficiency of 29.60, 30.65 and 23.69 % were found at the biomass consumption rates of 8, 7 and 7 kg.h-1 using maize cobs, sized wood and saw dust briquettes, respectively.

Performance of biomass combustor based drying system for ginger dry

A biomass combustor based dryer was evaluated with different biomass for drying of ginger. Biomass combustor based dryer consists of fuel hopper, combustion chamber, heat exchanger, grate for proper combustion of the combustible gas, chimney, ambient air inlet, hot air outlet and drying chamber. The system was evaluated at five fuel consumption rate (1 to 5 kg.h–1) and five air flow rate (100, 150, 200, 300 and 400 m3.h–1) using maize cobs, sized wood and saw dust briquettes for ginger drying. The experimental performances show that the hot air temperature inside the dryer vary between 36 to 81ºC for maize cobs, 53 to 85ºC for sized wood and 49 to 87ºC for biomass briquettes at tested air flow rate and fuel consumption rate in the system. The maximum efficiency of the system was found at the fuel consumption rate of 1 kg.h–1 and 400 m3.h–1 air flow rate using maize cobs, sized wood and saw dust briquettes as fuel respectively. The cost of operation of ginger drying at 1 kg.h–1 fuel consumption rate and 400 m3/h air flow rate was Rs. 32.76, 34.26, 34.76 and 55 per hour using maize cobs, sized wood, saw dust briquettes and mechanical drying system, respectively. Hence, the drying of ginger in biomass combustor based dryer using maize cobs at 1 kg.h–1 fuel consumption rate and 400 m3/h air flow rate resulted in better performance.

Development of Rice Husk and Saw Dust Briquettes for Use as Fuel

Development of Rice Husk and Saw Dust Briquettes for Use as Fuel

Study on Reduction of Blast Furnace Flue Dust Briquette Made with Fly Ash as Binder

Study on Reduction of Blast Furnace Flue Dust Briquette Made with Fly Ash as Binder

Kinetic investigation of self-reduction basic oxygen furnace dust briquettes using charcoals from different biomass

This work aimed to characterize charcoal, palm oil charcoal, eucalyptus bark charcoal, and basic oxygen furnace dust (BOFD) to produce self-reducing briquettes. It also intended to investigate the briquettes reduction kinetics, as the activation energy, and the controller mechanism. This approach using these biomass charcoal and steelmaking dust residue has not been reported in the literature. The BOFD was characterized by XRD, SEM-EDS, and ICP-OES. It was determined the content of ash, volatile materials, and fixed carbon in the charcoals. The briquettes were made with a stoichiometric percentage of carbon, 25%, and 50% excess of carbon. The reduction was conducted on thermobalance in the temperature range of 700−1100 °C. Isothermals were applied in each 50 °C with 25 min long to apply the kinetic method Forced Stepwise isothermal analysis (FSIA). The results showed that the BOFD is composed of 52.97 wt% total iron as magnetite, wustite and metallic iron. The kinetics analysis showed that the reduction of the self-reducing briquettes took place in two steps: the chemical reaction as controller mechanism at 700−800 °C with apparent activation energy between 62–138.6 kJ mol−1, and diffusion as controller mechanism with activation energies in the range of 333.4 kJ mol−1 and 450 kJ mol−1 at 850−950 °C, showing comparatively with charcoal that the palm oil charcoal and eucalyptus charcoal could be applied in self-briquettes reduction.

Recycling of the Steelmaking by-products into the Oxygen Converter Charge

Abstract In the technological process of the steelmaking plant, secondary products are produced in parallel with the production of the main product, which have the character of secondary by products or industrial waste. The major secondary products of steelmaking production include waste gases, process fluids, flue dust, sludge, slags and mill scales. The paper presents the results of research project directed to the utilization of demetallized steelmaking slag and oxygen converter flue dust in charge of top blowed oxygen converter. The influence of demetallized slag additions on slag regime in converter and chemical composition of final slag is described and discussed. Recommendations concerning amount of demetallized slag additions are also presented. Flue dust was recycled in form of briquettes. No significant effect of the recycling demetallized converter slag and flue dust briquette on process of hot metal refining and on quality of produced steel were recorded. Regarding the achieved results it can be confirmed that the use of the secondary products like demetallized slag and convertor flue dust in form briquettes, is environmentally acceptable as well as the use of natural materials and poses no increased risk to human health or the environment.

Manihot glaziovii-Bonded and Bioethanol-Infused Charcoal Dust Briquettes: A New Route of Addressing Sustainability, Ignition, and Food Security Issues in Briquette Production

Most of the citizens in developing countries use charcoal for domestic cooking and small-scale enterprises because of its high calorific value, less smoke, and easy to transport. However, a lot of charcoal dust is generated from charcoal trading activities. The dust is left as heaps of solid wastes in urban areas and sometimes thrown in water streams, thus being a nuisance to both humans and the environment. This study aimed to develop and characterize charcoal dust briquettes bonded with wild cassava Manihot glaziovii and also use of bioethanol to enhance briquette ignition. The percentages of binder to charcoal dust were varied from 5 to 30%. Proximate analysis, density, ignition time, burning rate, burning time, and calorific value were determined. The density of the produced briquettes ranged from 0.67 ± 0 to 0.83 ± 0.1 g/cm3; percentage of moisture content varied from 3.4 ± 0.2 to 4.2 ± 0.2; ash content varied from 19.6 ± 0.6 to 21.5 ± 0; percentage volatile matter ranged from 19.8 ± 0.3 to 24.3 ± 0.4; and percentage fixed carbon ranged from 51.9 ± 1.1 to 55.3 ± 0.2. The calorific value ranged from 17.7 ± 0.7 to 19.7 ± 0.3 MJ/kg, ignition time 139 to 163 s, and burning rate 0.3 to 0.7 g/min while water boiling time varied from 14 to 19 min and burning time from 85 to 116 min. Ignition test revealed that bioethanol ratio of 15 mL to 56 g of the briquette showed the best briquette ignition characteristics. It was further found that the amount of binder used influenced the combustion properties of the briquettes. This study also showed that charcoal dust could be compacted to briquettes using Manihot glaziovii as a binder. The overall performance of the briquettes showed that 5% binder gave the best results in terms of combustion characteristics.

Biomass: Turning Agricultural Waste to Green Power

People have an essential need of energy to cook. Presently, in developing countries, this requirement is met by directly burning wood derived products in fires and stoves. Many of the developing countries produce huge quantities of agro residues but they are used inefficiently causing extensive pollution to the environment. In rural areas, areca leaves are usually cut and dumped at the bottom of the areca trees or used as temporary roofing material. In order to explore the significance of areca leaf as an alternative for fuel, in this experimental work, areca sheet briquettes were prepared using size of 1700µ and above with sawdust as additives and wheat flour as binder. The various parameters of areca sheet briquettes were established using IS1448-7 for finding the GCV as well as proximate and ultimate analysis using IS 1350. According to the test results of the analysis, briquettes of areca sheet of 1700µ and above with sawdust as additive exhibited gross calorific value of 14.82MJ/kg. The moisture content is 5.37% and the percentage content of ash, volatile matter, and fixed carbon was 13.97%, 78.88%, and 2.48%, respectively. The percentage content of hydrogen, nitrogen, sulphur, and oxygen from the ultimate analysis are 6.67%, 0.52%, 0.60%, and 18.48%, respectively. The results thus obtained were then compared with the commercially available saw dust briquettes and the comparison results were quiet satisfactory. Hence, it can be concluded that briquettes produced from areca sheets of 1700µ and above, with sawdust as additive would make a good biomass briquette.

Influence of processing conditions on the quality of briquettes produced by recycling charcoal dust

Physical and thermal properties of briquettes produced by recycling charcoal dust under different processing conditions have been reported in this study. The main aim was to investigate the effects of the binder and processing conditions on the properties of briquettes. The effect of adding molasses binder on combustion properties of the briquette was first assessed. Then by fitting experimental data, mathematical models to predict gross calorific value, ash content, moisture content, relaxed density and shatter index with respect to binder mass fraction, drying temperature and compaction pressure were developed. All briquettes properties were predominantly affected by amount of molasses used. Molasses mass fraction increment in briquette results in significant increment in ash content, moisture content, relaxed density and shatter index and significant reduction in gross calorific value. Drying temperature did not have major influence on briquette properties except moisture content. Compaction pressure (50–150 MPa) used in this study had negligible influences on all briquette properties. Therefore, such high pressure which involves energy consumption is not necessary during production of charcoal dust briquettes. Optimized values of gross calorific value and shatter index were 29.031 MJ/kg and 80.363%, respectively, for 50 MPa compaction pressure, 29.512 °C drying temperature and 10% molasses mass ratio.

Recovery rates of iron, nickel, and chromium via iron-bath reduction of stainless steel dust briquettes based on corundum crucible erosion balance analysis

The leaching of chromium from stainless steel dust (SSD) is deleterious to the environment. To address this issue, the reduction of SSD briquettes can be employed to effectively extract chromium. The recovery rates of iron, chromium, and nickel via iron-bath reduction of SSD briquettes were determined using X-ray fluorescence spectroscopy, X-ray diffraction, and scanning electron microscopy measurements. First, the effects of basicity and contents of silicon, iron, CaF2, and carbon on the recovery rates of the three metals were analyzed using the slag amount prediction model, which was originally established from the Al2O3 balance of corundum crucible erosion behavior. Second, the effect of feeding mode, i.e., whether steel scrap and SSD briquettes were simultaneously added, on the recovery rates was discussed in detail. Third, the iron-bath reduction of SSD briquettes was thermodynamically analyzed. The results indicated that the recovery rates of the three metals are greater than 95% those of using a basicity of 1.5 and 6.0% CaF2, 15% carbon, and 7% ferrosilicon. The recovery rate of chromium increases twofold with the addition of ferrosilicon. The feeding mode of adding briquettes and steel scrap simultaneously is better for recovery of metals and separation of the metal and slag than the feeding mode of adding steel scrap firstly and then briquettes.

Optimization of the Stainless Steel Dust Briquette Reduction Process for Iron, Chromium, and Nickel Recovery

Abstract The recovery of iron, chromium, and nickel from stainless steel dust (SSD) has attracted considerable attention for their utilization as secondary resources in the ever-growing field of steelmaking. This paper investigates the reduction process of SSD briquettes in iron-baths in detail in order to determine the optimum processing parameters. A novel method of analysis by studying the erosion behavior of a corundum crucible was adopted to accurately calculate the recovery rate of the metals, and the effect of the parameters on the triple metals recovery rate was determined by orthogonal testing. The results show that the most important factor for the SSD briquetting process is water, followed by sucrose, carbon, and pressure. The optimum parameters of the SSD briquetting process are 13 wt% sucrose, 13 wt% water, 11 wt% carbon, and 30 MPa pressure. The compressive intensity was found to be 27.6 MPa. When a basicity of 1.6, 17% carbon, 5 wt% ferrosilicon, and 6% CaF2 were used in the SSD briquette reduction process, the triple metal recovery rate was in the range of 94 –100 %, 90 –100 %, and almost 100 %, respectively.

An investigation into a laboratory scale bubble column humidification dehumidification desalination system powered by biomass energy

This article describes a biomass powered bubble column humidification-dehumidification desalination system. This system mainly consists of a biomass stove, air heat exchanger, bubble column humidifier and dehumidifier. Saw dust briquettes are used as biomass fuel in the stove. First level of experiments are carried out in bubble column humidifier with ambient air supply to select the best water depth, bubble pipe hole diameter and water temperature. Experiments are conducted by integrating the humidifier with the dehumidifier. Air is sent to the humidifier with and without pre-heating. Preheating of air is carried out in the air heat exchanger by using the flue gas and flame from the combustion chamber. It is observed that the humidifier ability is augmented with the rise in water depth, water temperature, mass flow rate of air and cooling water flow rate, and reduction in bubble pipe hole diameter. It is found from Taguchi analysis that the water temperature dominates in controlling the humidifier performance compared to other parameters. Better specific humidity is recorded with a bubble pipe hole diameter of 1mm, water depth of 170mm and water temperature of 60°C. Highest distillate of 6.1kg/h and 3.5kg/h is collected for the HDH desalination system with preheated air and direct air supply respectively. Recovery of waste heat using an air heat exchanger reduces the fuel consumption from 0.36kg to 0.2kg for producing 1kg of distilled water. Lowest distilled water cost of 0.0133US$/kg through preheated air supply and 0.0231US$/kg through direct air supply is observed. A correlation is developed to estimate the mass transfer coefficient and it agrees with the maximum deviation of 9% from experimental results.

Effect of slag on strength of direct reduced iron produced with dust briquettes

The process of dust treatment with rotary hearth furnace is widely used in China, but the Direct Reduced Iron (DRI) produced with dust briquettes is prone to cracking, low strength and even crushing. So, the study on metallized pellets consolidation mechanism has an important guiding significance for the production practice. Mixture of conventional dusts briquettes were roasted at 800∼1300 °C, then their compressive strength was measured. SEM-EDS analysis and FactSage simulations were done to research the effect of slag phase. The results indicated that DRI strength increases with increasing temperature and decreases with increasing carbon content. Changes of FeO and MnO content could significantly reduce the liquidus temperature of the slag. Liquid slag could bond all kinds of mineral particles and make metallic iron to form interconnected metallic iron bonding phase like network which is the skeleton to ensure the high strength.

Utilization of Animal Power for Low Density Briquettes Production

Draught animals have been the backbone of Indian agriculture through ages for supplying draught power. Animal operated implements available in the country are primarily meant for field operation and haulage. Therefore animals remain idle for a considerable period for which the farmer continues to provide fodder and shelter. It is estimated that the annual use of animals is limited to 300–350 hours only but the potential use of animal in a year is nearly 1800 hours. To achieve this target an appropriate, cost effective and easy to operate biomass briquetting machine operated by animal power rotary mode unit was developed. The machine was tested to produce low density briquettes by different biomass like charcoal, paddy husk, pigeon pea stalk and saw dust. On the basis of proximate analysis charcoal briquette has highest calorific value of 4480 Kcal/kg followed by pigeon pea stalk, saw dust and paddy husk having calorific value of 4200, 3890 and 3200 Kcal/kg respectively. The highest machine efficiency was 88.33% for charcoal briquette followed by 85.76%, 86.00% and 83.20% for paddy husk, pigeon pea stalk and saw dust briquette respectively.