Production Of Cast Iron Research Articles

Cupola Furnace Slag: Its Origin, Properties and Utilization

A cupola furnace is the most frequently used furnace aggregate for cast iron production. A by-product of the production of cast iron in cupola furnaces is cupola slag. Its amount is 40–80 kg per 1 tonne of the produced cast iron, and that is one of the reasons why this material is not as favoured as, for example, the blast-furnace slag. The purpose of this article is to provide the basic information on the formation of slag in a cupola furnace, and its chemical composition, structure and current potential applications. The greatest potential for the use of cupola slag is in the building industry; therefore, a section of the present article deals with the property that plays an important role particularly with regard to the use of slags in the building industry, i.e. the slag hydraulicity. The achieved results indicate that the hydraulicity of the cupola slag is incomparable with the hydraulicity of the blast-furnace slag; this may be associated with the problems that arise when the slag of this type is used in the building industry. The authors used the air-cooled as well as granulated slags from cupola furnaces in the production of concrete that was made from the slags alone. While the air-cooled slag may be used as a partial replacement for the blast-furnace slag in concrete mixtures, the use of granulated slag from cupola furnaces as a replacement for granulated blast-furnace slag in cement-free concrete has not proven to perform well.

Jarosite wastes reduction through blast furnace sludges for cast iron production

Jarosite is a dangerous waste derived from the hydrometallurgical route of zinc production, and it cannot be safely disposed of due to its acidic pH and the risk of toxic metal leaching. A new process at laboratory scale for the utilization of jarosite sludges is proposed, with the aim to obtain cast iron and an inert slag, using blast furnace sludges as reducing agent. Jarosite-reducing agent mixes were reduced in a muffle furnace at 1500 °C for 15 min. Two reducing agents were used: pure graphite (as control) and blast furnace sludges. Two CaO concentrations (5, 15%wt. on jarosite mass) and four equivalent C concentrations (7.5, 15, 30, 60%wt. on jarosite mass) were analysed. Cast iron was obtained from all of the mixes, but the highest reduction yield was obtained at 15%wt. equivalent C. The slag obtained from the control batch had a fully crystalline structure, while the one related to the sample with BF sludges showed an incipient vitrified structure, that could prevent the leaching of hazardous elements. The best process parameters to profitably obtain cast iron and a glassy slag are 15% of equivalent C, 5% CaO and blast furnace sludges as reducing agent.

Recycling of Dispersed Metal Wastes in Rotary Furnaces

The recycling of dispersed metal containing wastes is a considerable problem, as their accumulation in dumps today is commensurate with the volume of ore extraction. Several methods and technologies are developed to recycle metal containing wastes but almost all of them require the preliminary preparation of wastes resulting in an increased price of the recycled metals. Furthermore, it is especially difficult to recycle dispersed multicomponent wastes and, therefore, the problem of developing effective, flexible and reliable technology for recycling of dispersed metal containing wastes is still a pressing one. The article presents an alternative method of recycling dispersed iron-containing wastes based on a continuous solid-liquid process of iron oxides reduction in rotary tilting furnaces (RTF). The new method allows the processing of waste of almost any composition and state: from metal lumps to oxide and multicomponent (chips, scale, sludge, etc.) wastes, contaminated with moisture, oils, organic impurities without their preliminary preparation (cleaning, homogenization, pelletizing, etc.). The result of recycling is the production of cast iron or steel ingots or required casting alloys. Some features of technology are considered, including the gas flow and motion of charge metal particles within the RTF. Process parameters providing high metal output are established.

Method for determining blast furnace tuyere zone blackness degree on pulverized coal fuel injection

Pulverized coal fuel (PCF) supply is one of the modern methods of improving the cast iron production technology in blast furnaces (BF). It has a significant effect on the heat exchange in the tuyere zone (TZ). The known method of radiant heat transfer calculation in TZ accounts only for the ash particle effect on the TZ blackness degree. The aim of this work is to develop a method for determining TZ blackness degree and to investigate the effect of different factors on this value. The work was based on the elements of the proven method of calculating heat exchange in boiler furnaces. Parametric sensitivity was investigated by alternately simulating an error in each of the input values and determining its effect on the sought value. By analysing the processes, the authors have derived dependences for obtaining the concentration of ash particles and triatomic gases and determined the degrees of TZ blackness by Bouguer’s law simultaneously taking into account the radiation of the burning coke and ash particles, and triatomic gases. It has been established that an increase in the PCF consumption from 0 to 250 kg/t of pig iron changes the TZ blackness degree from 0,067 to 0,243; and a 1 % increase in the pressure, concentration of triatomic gases, ray effective length, TZ temperature and ash particle size changes the TZ blackness by 0,714 %, 0,151 %, 0,72 %, –1,557 % and –0,176 %, respectively. The calculations have shown that the effects of coke particles, triatomic gases and ash particles on the sought value are approximately equal. In contrast, when the conventional method is applied, it results in an approximately 2-time underestimation of the values, while even for evaluation calculations, the maximum permissible error is 10–15 %. The developed method accounting for all factors has the maximum error of 5 %. It is important for designing tuyeres and TZ refrigerators.

Determination of structure and properties of ferriferous sand of aluminous production for search of ways for their processing

The need to involve the production wastes – ferrous sands of the Pavlodar aluminum plant into the processing is associated not only with environmental protection, but also with the necessity to increase alumina production, complex waste utilization and the sintering process normalization. For high-iron bauxites effective using in the early stage of the process, the maximum separation of ferriferous sands from bauxite is carried out. The waste flow of ferriferous sands is 50 t/h, which are 10 % from general flow of feed bauxite. It contains up to 60 % of iron oxide and 17 % of aluminum oxide, which is irretrievably lost, reducing the overall extraction of alumina from bauxite. To involve production wastes in the processing, detailed physicochemical studies of the composition of ferriferous sand by methods as follows: X-ray, optical, thermal, phase and chemical analyzes of the fractions from +1 to -0.15 mm were carried out. It is shown that with the decrease of the fraction, the content of iron oxides (56.3-60.9 %) increases, and the content of aluminum oxide decreases (13.4-10.4 %). X-ray analysis of the averaged sample showed that the main iron-containing components in the ferriferous sands are, %: hematite 29.1; hetite 8.6; magnetite 6.19; siderite 8.14; as well as pyrite and andradite – by 2.58. Aluminum-containing phases are, %: gibbsite 11.6; serpentine 8.94 and kaolinite 7. The composition also includes concomitants, %: quartz 5.8; calcite 8.49 and gypsum 3.7. The performed thermal analysis also confirmed the presence of identified phases. The decomposition and oxidation temperatures of the components that occur with increasing temperature were determined. The obtained data on the phase composition and its transformations are necessary when developing methods for the ferriferous sands utilization. An analysis of the physicochemical data of ferriferous sands’ composition has shown that they can be considered as a potential raw material for pigments and cast iron production. The development of new technical solutions aimed at the involvement of production wastes – ferriferous sands in the process will increase the profitability of the existing alumina production by low-quality high-iron bauxite processing.

An investigation of a single-stage red mud reducing roasting process with the cast iron and aluminate slag production

An investigation of a single-stage red mud reducing roasting process with the cast iron and aluminate slag production

Reduction melting of metal-containing industrial wastes without carburizing of metal alloy

Metallurgical processing of group iron-manganese-chromium-containing raw materials and the production of steel and alloys are the fundamental basis of the industry. At the same time, they represent a significant part of the gas emissions into the atmosphere and solid waste accumulated in dumps. The traditional technology for the production of steel and alloys is based on the use of agglomerated raw materials, as a result of the preparation and processing of which the formation and accumulation of small and metal-containing waste takes place. For today, effective processing of them remains the problem of metallurgical sector. The present work is devoted to solving this problem on the basis of accumulated metal-containing waste of metallurgical and mining enterprises. Experimental studies on the preparation of ore-coal pellets from waste, their metallization and reduction melting in laboratory installations were performed. Based on the analysis of the results of experimental studies, a technology for reducing smelting of metal-containing waste has been developed. It is shown that as a result of the technology implementation, high-quality steels and alloys without carburizing of metal can be obtained, bypassing the stages of production of cast iron and high-carbon alloys. The experimental research method consists in preparation of dispersed metal-containing and carbon-containing industrial wastes of ore-coal mixtures with stoichiometric consumption of coal for recovering recoverable metals, and the obtaining of ore-pellets that are further subjected to metallization and reduction melting. As a result of the implementation of the proposed technology, samples of manganese-containing alloy steels with a carbon content in the range 0,44-0,52%, manganese 3,5-7,2%, and chromium-containing alloy steels with a carbon content in the range 0,42-0,46%, chromium 4,45-9,27% were received.

Experiment for Use of Bratsk Aluminum Plant Technogenic Waste as a Reducing Agent During Cast Iron Smelting

The fundamental possibility of recycling fluorocarbon-containing waste generated in producing primary aluminum is demonstrated. Technogenic waste of electrolytic production may be used as raw material for other branches of industry, and, in particular, it may compete with oven coke in the steel industry. When using RUSAL Bratsk fluorocarbon-containing waste (carbon foam flotation tailings, gas cleaning slurry, and electric precipitator dust) as reducing agents, good metal extraction from iron-ore concentrates of Korshunovskii Mining and Enrichment Combine is achieved. Research results show that use of waste when smelting in a briquetted form (carbon content on average up to 55%) permits extraction of up to 94% iron, which is comparable with experience in the use of oven coke for cast iron production.

Basic areas of the secondary energy resources use in the blast-furnace ironmaking and application of heat pumps

Under the present-day conditions of blast-furnace shop operation, the use of low-potential SERs seems to be the most promising measure with regard to reduction of cast-iron production cost. Proposed measures on improvement of blast-furnace gas calorific power due to the reduction of its moisture content allow the blast-furnace air temperature increase and coke consumption reduction. Also proposed is partial transfer of excess heat from the blast-furnace gas to combustion air by means of the system of heat pumps, which allows increase in calorimetric combustion temperature.In this paper, main parameters are calculated of the heat pump system operation under the conditions of blast-furnace shop at the increased top gas temperature. This paper presents heat pump system operating efficiency and determines conversion factor for the specific conditions (COP).

Power supplies for dual-frequency induction melting of metals

The article discusses the benefits of multi frequency induction melting in the production of synthetic cast iron, structural (electric circuit) principles of dual frequency Power supplies of melting systems. The ways of electric power regulation of low frequency and high frequency components of the current in the inductor sections of furnace are demonstrated, namely power rescheduling at the metal melting stage, alloying stage and decarburizing of synthetic cast iron.

Characterization of cast iron and slag produced by jarosite sludges reduction via Arc Transferred Plasma (ATP) reactor

Jarosite process is the most widely adopted method for zinc production via a hydro-metallurgical route. Jarosite sludges are classified as hazardous waste by the European Waste Catalogue. Up to now, jarosite sludges were stored in lined pounds within the zinc refinery, representing a pollutant source for subsurface and groundwater. Landfilling is possible only after a stabilization treatment that covers twice the amount of waste to be disposed of. In this paper, a new method to recover the residual iron content within jarosite sludges through an Arc Transferred Plasma (ATP) reactor is presented. Reduction of jarosite sludge leads to the production of cast iron, accompanied by the formation of a glassy inert slag that can be easily disposed of in inert waste landfills, or better, recovered as alternative to stone materials. This process results in the recovery of the whole amount of jarosite sludges, reducing to zero the waste to be disposed of.

Basic areas of the secondary energy resources use in the blast-furnace ironmaking and application of heat pumps for utilization of sensible heat of the furnace top gas

Reduction of specific energy consumption at cast-iron production is the topical issue over several decades. One of basic areas of the specific energy consumption reduction is the specific coke consumption reduction due to injection of pulverized coal fuel (PCF). Under the present-day conditions of blast-furnace shop operation, the use of low-potential SERs seems to be the most promising measure with regard to reduction of cast-iron production cost. Proposed measures on improvement of blast-furnace gas calorific power due to the reduction of its moisture content allow the blast-furnace air temperature increase and coke consumption reduction. Also proposed is partial transfer of excess heat from the blast-furnace gas to combustion air by means of the system of heat pumps, which allows increase in calorimetric combustion temperature. In this paper, main parameters are calculated of the heat pump system operation under the conditions of blast-furnace shop at the increased top gas temperature. This paper presents heat pump system operating efficiency and determines conversion factor for the specific conditions (COP).

Porcelain Prototypes: Attributing the Models of Ural Art Iron Casting

This article considers one of the most relevant issues in the study of art casting from cast iron. Due to the fact that the administration and owners of the Kasli Iron Works responded in their strategies to the tastes of different consumers and also because they treated their production as part of their advertising campaign for the plant meant to demonstrate the capacities and quality of their main production, i.e. military and agricultural, there was no established plan for the product range. This is proved by the great variety of models different both stylistically and technically. With a few exceptions, the illustrated albums and pricelists of the Works provided information about the authors of the products. A systematic study of the authorship of Ural art casting production started in the 1980s but until today, there are considerable gaps in researchers’ knowledge about the authors of the models. The article considers sources of cast iron works, namely, models borrowed from porcelain production. Owing to its relatively low price and mass production, by the second half of the nineteenth century, the European and Russian markets of porcelain were full of allegoric statuettes and figurines focusing on everyday themes. Such porcelain works owned by the administration members of the Kyshtym mining district became models or prototypes for the cast iron products of the Kasli Iron Works. Porcelain prototypes continued to be used during the Soviet stage of the Works’ history. In those days, it did not only use existing models but collaborated with porcelain artists, such as E. A. Janson-Manizer, O.P. Tayezhnaya-Cheshuina, L.P. Azarova, etc.

Analysis of Cooling Curves of Nodular Cast Iron

The solidification of cast iron is a complex process with characterized entrance and marginal conditions. Thermal analysis is one of the processes that allows us to observe the solidification of alloys. There is a possibility of gaining information about the melted cast iron quality and predicting the final properties of the cast by evaluating the scanned cooling curves by solidification (stable and metastable system). This article deals with the study and analysis of cooling curves taken from production conditions of a foundry during ductile cast iron production. The aim is to discover the reproduction and reliability of the thermal analysis results of cast iron. The study of the progress of the cooling curves and their first derivation to follow the reactions of the curves to changing factors in the production process.

Thermal and chemical analysis of massive use of hot briquetted iron inside basic oxygen furnace

The integrated steelmaking cycle based on the blast furnace-basic oxygen furnace (BOF) route plays an important role in the production of plain and ultra-low carbon steel, especially for deep drawing operations. BOF steelmaking is based on the conversion of cast iron in steel by impinging oxygen on the metal bath at supersonic speed. In order to avoid the addition of detrimental chemical elements owing to the introduction of uncontrolled scrap and in order to decrease environmental impact caused by the intensive use of coke for the production of cast iron, HBI (hot briquetted iron) can be used as a source of metal and a fraction of cast iron. Forty industrial experimental tests were performed to evaluate the viability of the use of HBI in BOF. The experimental campaign was supported by a thermal prediction model and realized through the estimation of the oxidation enthalpy. Furthermore, the process was thermodynamically analyzed based on oxygen potentials using the off-gas composition and the bath temperature evolution during the conversion as reference data.

Thermophysical aspects of reclaimed moulding sand addition to the epoxy-SO2 coremaking system studied by Fourier thermal analysis

The most important advantage of foundry purpose moulding sand is that it can be reclaimed and reused through the casting manufacturing process. Supplying the foundry with a new source of material, sand reclamation brings along both environmental and economic advantages. Utilization of used sand can be considered as a common technological routine in the production of most types of chemically bound moulding materials. The epoxy-SO2 process is prevalent in the processing of cast iron engine components worldwide. Based on its excellent properties, it is mainly suitable for producing internal sand cores with complex geometry. Even though reclaimed sand addition is an active and well-functioning feature in ferrous foundries, the scientific and thermophysical background of its effects on the casting process is yet to be explored. In this work, the thermal aspects of different reclaimed sand levels in the epoxy-SO2 moulding system were examined. Thermogravimetry and differential thermal analysis of the epoxy-SO2 and reclaimed sand in focus were carried out to obtain basic understandings about their high-temperature behaviour. A state-of-the-art Fourier thermal analysis method presented in a recent paper was used at temperatures corresponding to actual cast iron production (1300 ± 10 °C), contrary to the previous tests at the typical temperature range of aluminium melt processing (660 ± 10 °C). By the right of the method, the effects of reclaimed sand addition on the heat absorption (cooling) capacity of the epoxy-SO2 moulding mixtures were investigated.

COMPUTER MODELING OF STRAINS ON PHASE BOUNDARIES IN DUCTILE CAST IRON AT HOT EXTRUSION

The computer modeling of the strain distribution in the structure of ductile iron with ferrite-pearlite matrix and inclusions of spherical graphite dependence on increasing degree of deformation during direct hot extrusion was researched. Using a software system of finite-element analysis ANSYS the numerical values of the strains at the phase boundaries: ferrite-perlite, graphiteferrite and also inside the graphite inclusions were defined. The analysis of the strain distribution in the investigated structures was performed and local zones of increased strains were discovered. The results of modeling are compared with metallographic analysis and fracture patterns. The obtained results could be used in the prediction of fracture zones in the cast iron products.

Inoculant enhancer to increase the potency of Ca-FeSi alloy in ductile cast iron

Cast iron is at more than 70% of total world castings production, with ductile cast iron at a rate of 25% (close to aluminium and steel castings together). Rare earth elements [REE] have important contributions in ductile cast iron production, generally to neutralize tramp elements that interfere with the nodulizing effect of Mg, to assist in nodulizing by providing a supplementary boost to Mg and to assist in the inoculation effect in nucleating graphite, depending on charge materials quality and castings requirements. With less REE available, due to their world crisis, their future use in foundry alloys should be carefully thought out and other treatment methods need to be investigated. Inoculation is one of the most important metallurgical treatment applied to the molten iron immediately prior to casting, with direct effects on the primary structure. Generally, inoculation is applied to forestall solidification at excessive eutectic undercooling degree, favourable for carbides occurrence. The enhancement of the 75% Ca-FeSi alloy by the contribution of an addition of sulphur, oxygen and oxy-sulphides forming elements appears to be a better and more effective inoculation solution compared to using more expensive inoculating elements, such as the REE or Ba containing alloys. This combination alternative led to the lowest carbides amount, the highest nodule count, nodularity and graphite compactness degree. It was more effective than an equivalent addition of a REE, Ca-FeSi alloy, or compared to Ca, Ba-FeSi and Ca-FeSi variants, but with a 60% to 77% lower alloy consumption.

The revolution of cast iron production process

The revolution of cast iron production process

Utilization of Slags from Foundry Process

The melting of steel or cast iron is one step of the foundry process. The foundry industry uses different types of furnaces, and metallurgical slags are products of the pyrometallurgical processes defecting in these furnaces. Furnace slag is a non-metallic by-product that consists primarily of silicates, alumina silicates, and calcium-alumina-silicates. As a by-product of the melting process, furnace slags vary considerably in form depending on the melted metal furnace types, and slag cooling method used. Most quantity of slags from the foundry processes are created in a cupola furnace that is used for cast iron production. An electric arc furnace is usually used for steel production, but it can be used for cast iron production as well. Universal use features an electric induction furnace. Slags from the melting processes in a foundry can be in the form of gravel, or the slag from a cupola furnace can be granulated. The utilization of slags from foundry processes is very delimited in Slovakia because of their quantity. This article deals with the possibility of using foundry slag as a binder in civil engineering. A basic property of a binder in civil engineering is its hydraulicity, which can be given by compression strength. Four metallurgical slags were tested. The values of the compressive strength of the slags were low, but addition cement to the slags resulted in a strong increase in the value of the compressive strength.