Brick Lining Research Articles

Investigation of End-of-Life Chrome-Magnesia Refractories Using X-Ray Computed Tomography

The lifespan of refractory linings is a major industrial concern for safety, on-line availability, and financial reasons. In copper smelting, batchwise operating matte converters are the furnaces that pose the greatest challenge when it comes to refractory wear and lining life. In this work, the structure and morphology of used magnesia–chrome bricks were studied using X-ray computed tomography and mineralogical techniques. The bricks were taken from various locations of an end-of-life brick lining of an industrial Peirce–Smith converter, after a normal campaign at Boliden Harjavalta smelter (Finland). The results show that it is possible to visualize in 3D, e.g., porosity, metal-containing phases, and refractory magnesia in the used bricks. Different digital images, such as cross-sections and average volume fractions, were used as a non-destructive method to characterize the bricks’ internal structure. The metal/matte infiltration in the open porosity was found to differ based on the location in the converter, with some bricks having no metal/matte infiltration and the tuyere line showing metal/matte infiltration at a depth of about 100 mm from the hot face.

From hydratable alumina bonded high chrome castables to shaped product for coal water slurry gasifier

The gasifier is a key equipment of coal gasification technology, enabling efficient and clean utilization of coal resources. However, the aluminum phosphate bonded high chrome brick lining in the gasifier experienced premature failure due to the migration of phosphate in reducing gases such as H2 and CO, as well as increased slag penetration and thermal spalling. In this study, a high chrome castable was prepared using hydratable alumina as a binder and fired at 1600 ℃ to replace the traditional phosphate bonded high chrome brick. The impact of curing temperatures (25℃, 40 ℃, and 60 ℃) on the properties of the high chrome castable was investigated, with corresponding hydrates examined through XRD, FTIR, TG-DSC, and SEM analyses. Results revealed that higher curing temperatures accelerated the hydration process of hydratable alumina. At higher curing temperatures, more well-developed micro-nano sized boehmite and bayerite phases were formed within the castables, filling their pores effectively and enhancing their properties after drying at 110 ℃. Moreover, during heat treatment these micro-nano sized hydrates decomposed into submicron/nano sized alumina which readily reacted with Cr2O3 to form (Cr-Al)2O3 solid solution. This phenomenon facilitated the sintering of castables fired at 1600 ℃ and optimized internal structure, ultimately leading to the enhanced mechanical properties and improved slag resistance.

Optimalisasi Pengendalian Rasio ICP Boat dengan Limbah Brick Ladle Converter Matte (Al2O3-SiO2) Menggunakan Simulasi Factsage

The purification process to increase the nickel content is carried out in a Pierce Smith converter through several stages, including charging, blowing, skimming, dry up, and casting, resulting in a nickel matte with a 75-78% nickel content. After casting, the nickel matte is stored in ladles, with each converter being able to accommodate the casting of 7 ladles, each with a capacity of about 15.5 tons. These ladles are made of carbon steel with a brick lining, consisting of castables on the walls and alumina brick on the bottom. Repeated pouring of matte into the ladles can cause surface erosion due to high heat input and matte friction, as well as chemical issues such as build-up. The refractory material in these ladles will undergo a total relining scheme, resulting in waste brick classified as B3 waste. The potential of the waste brick in the ladles is still quite high in producing residual nickel matte in a homogenized form. Therefore, the waste brick from the ladles will be considered to be mixed with ICP Boat with specific composition and distribution. The resulting mixture will be used as feed in the converter purification process by reviewing the variation of the waste brick to ICP Boat ratio using FactSage software simulation and validating the results through field experiments. FactSage software simulation recommends an improvement in the waste brick to ICP Boat mixture ratio of about 4.6-12% at a temperature of 1200°C to prevent the formation of spinel and olivine Keywords: Converter, ladle, brick, ICP boat, FactSage

Sulphur attack on RCC wall of sulphur pit

Sulphur attack is not a very popular damage mechanism in Reinformed Cement Concrete (RCC) structures. For Sulphur Recovery Units (SRU) of Hydrocarbon Processing Industry, it is not so. Here concrete pits are used for storing molten sulphur and hence concrete is exposed to corrosive materials. In BPCL- Kochi Refinery, during an internal inspection of a sulphur pit, bulging was noticed on the acid resistant brick lining. After removal of brick lining, sulphur attack was observed on RCC walls of pit. Full repair and refurbishment of the wall was carried out accordingly. As a case study approach, this paper deals with various aspects of sulphur attack on concrete including symptoms, damage patterns etc. It also includes materials & methodology adopted in refurbishment jobs. The paper shall impart awareness about sulphur attack damages to industry/technical experts.

Investigation of Inner Lining Loss and Correlation with Steel Structure Ovality in Rotary Kilns

The article delves into the application of laser scanning within the realm of engineering, concentrating its examination on rotary kilns. Through an in-depth case study, this article meticulously assesses the advantages inherent in utilising laser scanning technology and draws comparisons with conventional measurement methods. The overarching objective of the investigation is to unravel the intricate relationship between the deterioration of the rotary kiln liners and the ovality of the underlying steel structure. By meticulously analysing these aspects, this article seeks to contribute valuable insights into the understanding of this complex interplay in the context of engineering practices. As a measurement apparatus, a terrestrial laser scanner was used. The interior and exterior of the rotary kiln were measured. The primary focus object was inner-lining loss and the geometric characteristics of the cylindrical shells. The research uncovered significant disparities in inner lining loss between the sections. A correlation was found between the ovality and elimination of the inner lining. Due to the hypothesis of constant inner lining loss in the middle of the rotary kiln, the investigation found that the loss of brick lining was less than the value reported from the wells. This study offers significant information on the maintenance and repair strategies for rotary kilns, which have the potential to increase their efficiency and useful life.

Hydraulic modelling of irrigation canals for improved flow conditions in surface irrigation systems

ABSTRACT Surface irrigation is a widely utilized method for agricultural irrigation, but it often suffers from low conveyance efficiency. Improving flow conditions in surface irrigation systems is crucial for enhancing water distribution and optimizing crop production. This study presents a comprehensive hydraulic modelling approach aimed at improving flow conditions in irrigation canals. The analysis focuses on the Doho Rice Irrigation Scheme in Uganda and utilizes the HEC-RAS hydraulic model. Different canal conditions, including desilting and vegetation clearing, concrete lining, plastic lining, and brick lining, are evaluated for their impact on flow dynamics. The findings reveal that all four canal conditions lead to significant improvements in flow conditions compared to the current state of the canal. Plastic lining emerges as the most effective solution, resulting in a remarkable 48 % improvement in flow conditions. Concrete lining follows closely with a 37 % improvement, while brick lining shows a 39 % enhancement. Desilting and vegetation clearing contribute to a 20 % improvement in flow conditions. These results underscore the potential of hydraulic modelling in guiding the design and management of irrigation canals to ensure sustainable water use practices.

Thermal conductivity of porous refractory material after aging in service with carbon pick-up

Medium Density Insulating Boards, based on vermiculite, are used for the insulating lining of ladles in steel production. In service, carbon monoxide is generated from oxidation of neighbouring Magnesia – Carbon bricks and diffuses through the refractory brick lining to deposit carbon in the colder insulating lining via the Boudouard reaction. Characterization by laser flash and hot disk measurements of original and post-mortem samples reveals an approximate increase by 26% in the overall thermal conductivity of the board to 0.34 W m−1 K−1 at room temperature following 15 months service. This is attributed to carbon and chloride phases detected by X-ray fluorescence and energy dispersive X-ray spectroscopy in the outermost zone of the board, cut into three zones for analysis along the heat flow direction. The increase in thermal conductivity is reduced to 17% when the thermal gradient in service conditions is considered.

Modeling Conjugate Heat Transfer in an Anode Baking Furnace Using OpenFoam

The operation of large industrial furnaces will continue to rely on hydrocarbon fuels in the near foreseeable future. Mathematical modeling and numerical simulation is expected to deliver key insights to implement measures to further reduce pollutant emissions. These measures include the design optimization of the burners, the dilution of oxidizer with exhaust gasses, and the mixing of natural gas with hydrogen. In this paper, we target the numerical simulation of non-premixed turbulent combustion of natural gas in a single heating section of a ring pit anode baking furnace. In previous work, we performed combustion simulations using a commercial flow simulator combined with an open-source package for the three-dimensional mesh generation. This motivates switching to a fully open-source software stack. In this paper, we develop a Reynolds-Averaged Navier-Stokes model for the turbulent flow combined with an infinitely fast mixed-is-burnt model for the non-premixed combustion and a participating media model for the radiative heat transfer in OpenFoam. The heat transfer to the refractory brick lining is taken into account by a conjugate heat transfer model. Numerical simulations provide valuable insight into the heat release and chemical species distribution in the staged combustion process using two burners. Results show that at the operating conditions implemented, higher peak temperatures are formed at the burner closest to the air inlet. This results in a larger thermal nitric-oxide concentration. The inclusion of the heat absorption in the refractory bricks results in a more uniform temperature on the symmetry plane at the center of the section. The peak in thermal nitric-oxides is reduced by a factor of four compared to the model with adiabatic walls.

Optimization of Blast Furnace Throughput Based on Hearth Refractory Lining and Shell Thickness

Computational analyses were performed to optimize the furnace throughput, steel shell and lining thickness of a blast furnace. The computations were done for measured parameters within the hearth region as this is the vital zone of the furnace with high temperature fluctuations, molten iron, and slag production. The lining materials were namely 62% high alumina (A), carbon composite (B), silicon carbide (C) and graphite bricks (D) with thermal conductivities 2, 12, 120 and 135 W/(m∙K), respectively. It was observed that by varying the refractory lining thickness from 0.2–0.35 m, and furnace inside temperatures from 1873–2073 K, certain optimal conditions could be specified for the furnace under consideration. Silicon carbide and graphite brick linings which have higher thermal conductivities, melting points, good chemical and mechanical wear resistance were observed to be the best hearth lining materials. Due to the high thermal conductivities of these two materials, the hot face temperature levels of the lining materials would be lowered. Amongst the four lining materials employed, silicon carbide and graphite bricks when used with lining cooling systems could optimize the blast furnace for better performance, production, and longer campaigns.

New Insights Into Refractory Lining Wear Mechanisms on a 22MVA FeMn Furnace

During February 2020 Assmang Manganese Cato Ridge Works #2 furnace was demolished with the intention to rebuild the furnace after 9 years of operation. Assmang Mn #2 was installed with a GrafTech freeze lining in 2011. This lining technology has exceptionally long lifetimes on ferromanganese and silicomanganese producing furnaces and no reported dig-out or excavation findings have been published to date utilizing this technology. Prior studies mainly focused on lining wear on carbon “big-block “lining technology or “hybrid” carbon rammed/alumina brick linings. Assmang Mn currently utilizes this lining technology on both their #1 and #5 furnaces, with #5 furnace now in its 13th year of operation. The aim of this study was to identify the main areas of wear on the tap-hole areas and sidewalls but most importantly on the hearth. Over the lifetime of #2 furnace bottom plate lifting has been observed from the grillage beams. The exact reason for this phenomenon was not certain and possible reasons could only be established by demolishing the existing lining and noting findings. The results of this dig-out will outline the exact lining condition over its campaign life. It was found that there was no significant wear on the tap holes or sidewalls, but metal ingress was found into hearth refractories. The findings of this report will greatly assist Assmang Mn on all future lining design considerations as well as give insight to possible hearth wear mechanisms.

Comparative study of engineering aspects of fire brick and borosilicate glass block linings in design of reinforced concrete chimneys

Comparative study of engineering aspects of fire brick and borosilicate glass block linings in design of reinforced concrete chimneys

Detection of Blast Furnace Hearth Lining Erosion by Multi-Information Fusion

The blast furnace hearth refractories are exposed to complex chemical attack and thermal stress erosion, which will lead to the gradual failure of refractories. The campaign life of a blast furnace depends on its remaining hearth refractory lining, so it is very important to understand the remaining thickness of hearth refractory for prolonging the service life of blast furnace. In order to understand the damage of hearth refractory more accurately, a multi-information fusion method for measuring the refractory lining thickness of blast furnace hearth was proposed, which was based on the application advantages of impact echo technology, thermocouple and cooling stave heat flux intensity in blast furnace hearth. The influence of temperature change in different material layers of hearth on wave velocity was considered. In addition, the thickness of carbon brick lining of blast furnace hearth was detected by the method of multi-information fusion. It is found that the multi-information fusion thickness detection method improves the accuracy of thickness measurement compared with the impact echo thickness detection method.

Investigating the rehabilitation methods of Victorian masonry tunnels in the UK

The Victorian tunnels that lie on the nation’s railway network have been vital to facilitating a reliable rail service across the country for the past 150 years. However, some of these tunnels have started to challenge the existing network. These tunnels were originally constructed using several rings of brick masonry as a lining. After many years, these brick linings have started to degrade and bricks are becoming dislocated from their surrounding rings, falling on the tracks. These tunnels are also of an outdated gauge, this is slowing Networks Rails plans to modernize the rail network. Network Rail plans to electrify the rail network and increase the speed and size of trains, and these tunnels are considered a hindrance. Network Rail is looking for potential economically viable repeatable methods for resizing and relining these tunnels. An initial investigation into this problem is performed by examining case studies of tunnels that have been resized and relined worldwide, what was learned from this has subsequently been synthesized into a tunnel refurbishment method matrix. This problem is further examined in detail by modelling the enlargement of Whiteball Tunnel, mimicking the use of a Tunnel Enlargement Machine to analyzing the feasibility of this method. This preliminary modelling indicates that utilizing this innovative technology would be feasible if the appropriate support is put in place.

Study of recycle spent brick lining as refractory castable product

Every year INALUM has produced around 500-1000 ton spent brick lining which placed in the dump yard. After it has been placed, it sells to the third party. Spent Brick lining which has been cleaned has no or little harmful content and some chemical composition can be utilized as a new product as the refractory application in INALUM. Some research proves that spent brick has some good mechanical properties if applicated as concrete and INALUM’s spent brick production high enough to fulfill castable needs in INALUM in a year. The General flow process of castable making is sorting and drying, crushing and grinding, screening, mixing (with other aggregate and additive). With this general production, its predicted to produce earnings after taxes (EAT) around IDR 678.232.000 per year.

Using Castables of Improved Properties for Iron and Steel Production

Abstract: The use of unshaped refractory mixtures designed to prepare monolithic lining represents a progressive trend that often replaces traditional brick linings. Their advantage lies in the fact that a part of production operations, such as shaping and firing, is performed on the consumer's premises, which reduces production costs, increases productivity and saves energy. Moreover, the repairs of damaged linings using unshaped materials are performed more effectively and, most importantly, faster. Due to the fact that the monolithic lining is continuous, no degradation of material caused by corrosive environments occurs on three of its sides. It is only the contact surface that is affected. The production program of RMS Kosice s.r.o. includes a wide range of castables based on various raw materials with different cement contents. The paper deals with the practical applications of castables in heating units used to produce iron and steel.

Influence of heating and cooling rate on the stress state of the brick lining in a rotary kiln using finite element simulations

Rotary kilns for iron-ore pellets production are highly dependent on a well-functioned refractory brick lining. To improve the long-term capability of the lining, in-situ observations of the bricks' performance are desired, however, the harsh environment inside the rotary kiln makes it difficult or nearly impossible to study the lining during operation. By using numerical simulations as a tool, some of the problems encountered by the brick lining can be studied without limitation of the extreme conditions.In this work, stress state of the lining was studied under the influence of different heating and cooling rates, and different brick compaction cases. A finite element model was created for conducting the numerical simulations. The numerical model was calibrated for transient heat transfer. Temperature dependent material properties of the bricks and casing were used as input. The heating and cooling was controlled by temperature prescription on the boundary of the brick lining, while brick lining compaction by defining relative position of the bricks in axial and radial directions.The conducted numerical simulations showed that considerable tensile stress may appear in a large area of the brick during initial heating stage. The large tensile area corresponds well with the typical circumferential cracks experienced by the bricks. It was demonstrated that the compressive stresses counteract the development of tensile stresses. However, the compressive stresses may become very large in the initial stage of heating. The positive effect of lower heating rate was considerable on the tensile stresses, while influence on the compressive stresses was almost unnoticed. The hypothetical cooling rates showed that very high tensile stresses may occur on the surface of the bricks, potentially leading to surface spalling. Furthermore, it was demonstrated that axial compaction is highly important on the stress development in the lining, which, may not always be followed in practice. As a general conclusion, it is recommended to always achieve a tight compaction of the brick lining and to take measures for lowering the heating and cooling rates.The conducted work exemplifies behaviour of the brick lining for realistic heat transfer and material properties. The insight into the behaviour gives possibilities to make adjustments and directed investments for lowering risk of brick lining failure.

Investigation of Metal Air-Cooling Process as An Element of Thermal Processing

<p>Background: Nowadays on metal tempering and annealing its air cooling (AC) is realized inside furnace with forced coolant delivery. Scientific tools lack for metal AC study and design is substantiated. The aim of this work is to investigate technological and design furnace parameters influence on metal AC duration, as well as disclosure of metal AC heat engineering regularities. Materials and method: For study mathematical model of metal AC is used. It bases on solving the differential non-stationary heat conductivity equation in one-dimensional form for cylindrical ingots and lining. Results: For three lining design types and different technological parameters operation acceleration possibility due to lining design change was studied. It is found that with ceramic fibers on walls and roof acceleration is 31-45% and with all lining made of ceramic fiber it is 44-52% as compared with fireclay brick lining. For a furnace with hearth of fireclay bricks and ceramic fiber on the walls and roof, convective component varies from 10 to 30%; for lining completely consisting of ceramic fibers it is 10 - 25%. When using fireclay brick lining parts their inner temperature is higher than for ceramic fiber up to 50 °C. Conclusions: Significant furnace lining materials type influence on metal AC intensity is proved. Heat removal mechanism on metal AC in furnace is disclosed, by establishing heat proportion directly removed from metal by convection. It is found that radiant heat transfer between metal and fireclay brick part of lining goes less intensively than with ceramic fiber part. </p>

The effect of recycling coke oven tar on environmental pollution, coke quality, personnel and process safety

Oven charging is an important operation stage in coke making process which is also where most of the coal dust is commonly generated. Coal dust is seen as a major hazard due to its tendency to ignite explosively causing coal losses, environmental pollution and plant equipment damages. In this study, the effect of recycling coke oven tar addition over a loading range of 2– 8 wt.% was evaluated as a probable partial substitute for expensive coking coals. Operation under an optimum coke oven tar loading of 6 wt.% resulted in a remarkable reduction of coal fines of 56.8%. By reducing coal fines, there is a considerable reduction in coal dust that personnel are exposed to and a reduction in acid mine drainage when storing the discarded coal fines as well as a decreased likelihood of spontaneous combustion. In addition, coal dust can cause pneumoconiosis and other health related conditions. Good coke qualities compared well to other international benchmarks were obtained. Vital factors for coking pressure such as maximum dilatation and maximum contraction increased within the acceptable range of <30 and < 20 respectively. High coking pressures cause operational problems such as stickers and heavy-pushes, which result in the deterioration of the brick lining of the coke oven walls. Therefore, it is desirable that coke oven tar increase coking pressure within the acceptable range so that the life span of the coke ovens is not shortened.

Study on Thermal Operation and Design of Ring Furnace of the Pipe Rolling Plant

High productivity of rolling and pipe rolling mills, good quality of finished metal products is possible to provide in the presence of powerful heating furnaces, well heating the metal with minimal oxidation and decarburization. Such conditions are provided by ring furnaces which are widely used for heating the preparations at rolling of pipes, wheels and bands of the railway rolling stock. The purpose of the heat – receiving structure of the metal, providing a set of physical and working properties, or impart to these materials the ductility required for subsequent machining. The article deals with the design and thermal performance of the ring furnace operating at ChelPipe’s Pipe Rolling Plant No.2. The problems arising during the operation of the thermal unit are analyzed. The paper describes the calculation of heating of metal and heat balance of the ring furnace. In the course of the analysis of the results of design studies, the shortcomings of the existing heat recovery system are revealed and measures for the reconstruction of the furnace to reduce fuel consumption and increase productivity (replacement of the existing brick lining with fibrous, the use of regenerative burners, the use of non-water-cooled partitions, etc.) are proposed. The paper analyzes the design and thermal performance of the ring furnace for heating of pipe billets before rolling. It shows a heat balance of the ring heating furnace and provides measures for furnace reconstruction aimed at reduction in fuel consumption and increase in efficiency: replacement of the existing lining with fiber lining, use of regenerative burners, application of non-water cooled walls.

Unsteady-state moisture behavior calculation for multilayer enclosing structure made of capillary-porous materials

The paper studies unsteady-state moisture behavior of multilayer enclosing structure using discrete-continuous method. Modification of Gagarin’s differential moisture transfer equation is proposed. The proposed moisture transfer equation within one layer of a multilayer enclosing structure is a second-order differential parabolic equation with constant coefficients. Third-kind boundary conditions of moisture exchange are set for enclosing structure boundaries. Fourth-kind boundary conditions represented by moisture potential flows equality are set at the joint of two different materials. An analytical expression for moisture potential calculation in any enclosing structure section, at any time, under continuous control for temperature distribution, has been derived using discrete-continuous method. Calculations for multilayer enclosing structure consisting of clay brick base and lime brick lining have been made. The obtained results have been compared to calculation results obtained by well-known Gagarin’s unsteady-state method and Kozlov’s engineering method. It has been shown that the discrete-continuous method allows calculating unsteady-state moisture behavior of multilayer enclosing structures by analytical expression, and obtaining moisture distribution similar to Gagarin’s unsteady-state method, thus it can be used by design engineers in practice.