Production Of Cementitious Materials Research Articles

Lead removal from aqueous using carbon nanomaterials and reuse of the lead-loaded adsorbent as a filler material in cement production

Heavy metals are posing problems in the environment and one of them is lead. The disposal of lead in our water systems comes from industries such as the paint, mining, and electroplating industries. In this study, Carbon nanoparticles (CNPs) were synthesized from carbon soot by using a refluxed method. The CNPs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction pattern (XRD) Brunauer–Emmett–Teller (BET), Thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and Transmission Electron Microscope (TEM). Batch adsorption studies were carried out for lead adsorption. Pb2+ uptake fitted well with the pseudo-second-order kinetics model, while the adsorption isotherm fitted best to the Langmuir model, with a maximum adsorption capacity of 67.98 mg/g at 25 °C. The obtained thermodynamic parameters demonstrated that the adsorption of Pb2+ ions by carbon nanoparticles was exothermic and spontaneous. The spent adsorbent was then used in cement production, demonstrating that Pb2+-CNPs can be a promising material for cement production when its quantity exceeds 1.2 %.

Space-based Applications of Remote Sensing in Studying Open-pit Mining and Ecology at Non-metallic Mineral Deposits in Russia

Based on the remote sensing data, comprehensive information is provided on mining landscapes at deposits of mineral raw materials for production of cement, crushed stone, metallurgical fluxes, and asbestos products, which are in open-pit mining in the mining regions of Russia. Using high-resolution satellite images, the amount of mining transport equipment in quarries at non-metallic mineral deposits has been determined. The volume of diesel fuel consumed by dump trucks when removing rocks from quarries has been calculated. The volume of toxic substances released into atmosphere during the operation of quarry vehicles in the being developed deposits of non-metallic minerals has been established.

Combined sand eco-mortar reinforced with polyethylene Terephthalate: Behavior and optimization using RSM method

Today, economic and environmental interests have become imperative in construction works. Therefore, the use of substitute materials for natural aggregates or cement contributes to the preservation of natural resources and the reduction of carbon dioxide diffusion. The large quantity of dune sand available in the Algerian Sahara and the affordable cost of recycled aggregates and plastic waste encourage their use as a replacement for natural aggregates in the production of cementitious materials. The interaction of dune sand (DS) and recycled sand (RS) with the introduction of a polyethylene terephthalate (PET-F) fibre help to design a normative ecological material. The aim of the study was to explore and optimize the proportions of these materials to create an environmentally-friendly cementitious product. The strategy is based on the progressive substitution of dune sand by another originating from demolition waste at different rates: 0%, 25%, 50%, 75% and 100%, and a gradual rate of PET-F fibres, 20 and 30 mm from 0% to 2% with a step of 0.5%. In this article, we study the effect of the new composites on the physico-mechanical performance of the designed eco-mortars through several tests (spreadability, fresh density, porosity, capillary and immersion absorption, compression strength, and flexural strength). In addition, we utilise Response Surface Methodology (RSM) to predict approximate parameters that influence the properties of new cementitious composites. The results obtained show the significant benefit of the following rates: 50% SD, 50% SR and (0.5%, 30 mm) PET-F fibre. Thus, the RSM model correlates well with the experimental data, which has undoubtedly led to an improvement in the physical–mechanical characteristics of the eco-mortar studied. Otherwise, the proposed model reaches a high pertinence, with a good desirability coefficient of 0.917.

Mechanical performance of cement mortar with olive pomace aggregates and olive mill wastewater: an experimental investigation

This study investigates the potential use of olive aggregates (OA) in the production of cementitious materials as a substitute for natural sand to reduce excessive use of this resource. Two types of OA were used: OPA (olive pomace aggregates) and OPMW (OPA mixed with olive mill wastewater). The aim was to determine experimentally whether improvements in the mechanical properties of the produced lightened cement mortar could be obtained compared to the reference mortar. Laboratory tests were conducted on two series of mortar samples made by replacing 0%, 5%, 10%, and 15% of natural sand with both dry and saturated OA. The best results were observed in a mixture containing 5% of OPMW at the dry state, which had a marginal effect on the compressive strength of the produced mortar, reaching 33.50 MPa after 28 days of curing. However, microstructural analysis revealed low adhesion between the OA and the cement matrix at the interface transition zone (ITZ) after 28 days. Increasing the OA content was found to decrease the workability of the mixture while also increasing the porosity of the resulting lightened cement mortar. Additionally, the use of OA reduces ultrasonic pulse velocity and dynamic modulus of elasticity. Overall, the best results were obtained with the mixture containing 5% of OPMW at the dry state, which meets the standards for general use of building materials.

Thermal co-treatment of aluminum dross and municipal solid waste incineration fly ash: Mineral transformation, crusting prevention, detoxification, and low-carbon cementitious material preparation

Harmless disposal and resource utilization of hazardous industrial wastes has become an important issue with the green development of human society. However, resource utilization of hazardous solid wastes, such as the production of cementitious materials, is usually accompanied by a pretreatment process to remove adverse impurities that contaminate the final product. In this study, aluminum dross (AD) was thermally co-treated with another hazardous waste, municipal solid incineration fly ash (MSWI-FA), to synergistically solidify F and Na, control leaching of heavy metals, and remove chloride impurities. Significant crusting was observed when AD was thermally treated by itself, but not when AD and MSWI-FA were thermally co-treated. In the process of co-thermal treatment, the remaining Cl, Na, and K contents were reduced to as low as 0.3%, 1.8%, and 0.6%, respectively. CaO and SiO2 in MSWI-FA reacted with Na3AlF6 and Al2O3 in AD, and formed CaF2 and Na6(AlSiO4)6, which contributed to the prevention of crusting and limited the leaching concentrations of F and Na to below detection thresholds and 270.6 mg/L, respectively. In addition, heavy metals were well solidified, and dioxins were fully decomposed during thermal treatment. Finally, a sulfoaluminate cementitious material (SACM) with high early- and later-age strengths was successfully created via synergetic complementarity using thermally co-treated AD and MSWI-FA together with other solid wastes. Collectively, this study outlines a promising method for the efficient and sustainable utilization of AD and MSWI-FA.

Efisiensi Persediaan Kantong Semen Berbasis Metode MIN-MAX, EOQ, dan TWO-BIN di Packing Plant PT AKA

PT AKA is a multinational enterprise engaged in the cement industry. One of the supporting raw materials in cement production is cement bags. Demand for cement bags is directly proportional to the demand for cement. The production division has been experiencing the problem of inefficiency in determining the supply of cement bags. This study aims to evaluate the company's policy in controlling the supply of raw materials for cement bags by comparing the 3 Min-Max, EOQ, and Two-Bin methods. Quantitative data were used: demand for cement bags, storage, and ordering costs. Forecasting data calculations were performed using Minitab software. The results showed that the Min-Max method produced the optimal efficiency with a total inventory cost of Rp. 119,107,700 for 40 kg cement bags, and Rp. 35,528,720 for 50 kg cement bag.

Investigation of mechanical activation effect on high-volume natural pozzolanic cements

Abstract Mechanical activation is one of the most preferred methods to increase the reactivity of mineral, mining, and industrial wastes or materials with low pozzolanic content in cement production. The mechanical activation process of such materials takes a long time and requires high grinding energy. Although it seems like an advantage to using the materials in cement production by gaining reactivity thanks to mechanical activation, mechanical activation is a long duration and expensive process, causing an increase in cement production costs. In this study, a hybrid method is proposed for the mechanical activation of materials in a shorter duration and with lower energy consumption. A roller press and a hammer grinder were integrated before the laboratory type ball mill to realize the mechanical activation processes. To perform the mechanical activation processes in this way, two different hybrid grinding methods were tested and compared. Both methods activated volcanic tuff samples with low pozzolanic properties were investigated particle microstructures, energy consumption differences, mechanical activation durations and their effects on the cement performance, and mortar microstructures. The hybrid grinding method integrated with roller press and ball mill was determined to be the best mechanical activation method.

Metallurgical Wastes as Resources for Sustainability of the Steel Industry

The industrial pollution caused by metallurgical waste accumulation has a negative impact on the three environmental factors: soil, air and water. Therefore, the correct management of these wastes would lead to: protection of the environmental factors, the saving of natural resources and sustainability of the steel industry. The purpose of this paper is to assess the chemical and mineralogical compositions of metallurgical wastes landfilled in the Păgida slag dump (Alba County, Romania), for sustainability of the steel industry and metal conservation. The chemical compositions of the two waste samples were analyzed by the XRF (X-ray fluorescence) technique. According to the chemical characterization, magnesium oxide (MgO) has potential to be used as an additional and raw material in the cement industry. The presence of oxides such as CaO, SiO2 FeO and Al2O3 in the compositions of the metallurgical waste samples indicate that they have the potential for use as clinker materials in cement production. The iron and manganese contents from metallurgical wastes can be reused in the iron and steel industry. The presence of V2O5 and TiO2 is connected with the making of stainless steel, and for this reason they have the potential to be reused in the stainless steel industry. The predominant chemical compounds are SiO2, Fetotal, Cao and MgO. The mineralogical compositions were analyzed by the XRD (X-ray diffraction) technique. The mineralogical compounds presenting reuse potential in different domains are Fayalite, Magnetite, Magnesioferrite and Periclase. The mineralogical compounds from metallurgical wastes can be reused as: raw and/or additional materials in the process from which they originate (steelmaking); raw and/or additional materials in road construction and concrete production; pigments in paints; micronutrients in fertilizers; ore of iron, etc. Then, the theoretical assessments of the recovery potentials of the metals were estimated for slag dumps. Copper (Cu), vanadium (V), molybdenum (Mo) and nickel (Ni) have high recovery potential. The total economic value of the recovery potential of metals from slag dumps was assessed to be USD 1175.7440 million.

Interpretation of Chemical Analyses and Cement Modules in Flysch by (Geo)Statistical Methods, Example from the Southern Croatia

This study included the testing of normal (Gaussian) distribution of input data and, consequently, spatially interpolating maps of chemical components and cement modules in the flysch. This deposit contains the raw material for cement production. The researched area is located in southern Croatia, near Split, as part of the exploited field “St. Juraj–St. Kajo”. There are six lithological units: (1) alternation of marls and sandstones with inclusions of conglomerates, (2) marl, (3) calcsiltite, (4) calcarenite, (5) marl with nummulites, (6) debrites, and (7) clayey marl. All of them are deposited in the (a) northern and (b) southern beds. Only debrites are divided into the (a) western and (b) eastern layers. Those lithological units were divided technologically based on their cement modules (lime saturation factor (LSF), silicate module (SM), and aluminate module (AM)). The average thicknesses were analysed, followed by normality tests (Kolmogorov–Smirnov (K–S) and Shapiro–Wilk (S–W)) of the chemical analyses: CaO, SiO2, Al2O3, Fe2O3, MgO, SO3, Na2O, K2O, CaCO3 (%) and three cement modules (LSF, SM, AM), available in the six lithological units. The normality tests were applied based on a number of input data. The further interpolation was performed using two methods, kriging and inverse distance weighting, mapping CaO (%), SiO2 (%), and LSF (−) in three different lithological units. The interpolation methods were selected based on two criteria: (a) normality test pass or fail and (b) the amount of data. In total, 144 tests were calculated, including sets from 7 to 36 points. The results show the current situation in the quarry, after decades of production, making reliable the future predictions of cement raw material exploitation.

Natural fiber-reinforced light-weight cement blocks prepared from waste for sustainable development

Low density of the light-weight cement blocks offers an advantage in terms of dead load reduction, which is advantageous in structural design-reduction of size and numbers of load-carrying structural components is possible. Production of cement blocks, however, generally requires Ordinary Portland Cement (OPC) which creates harmful environmental impacts. Utilization of waste as alternative raw materials for cement production is a route to alleviate the problem. This research aims at synthesizing eco-friendly cement-like material for production of light-weight cement blocks. The cement-like material were prepared from eggshells, cockleshells, and rice husk ash (RHA). With high content of calcium oxide and silica, eggshells and cockleshells are potential sources of calcium, whereas RHA is a good source of silicon. Additionally, a fuel-efficient solution combustion technique was employed in synthesis of the cement-like material. Phase identification analysis of the synthesized powder indicated that tri-calcium silicate (C3S), di-calcium silicate (C2S), tri-calcium aluminate (C3A),and tetra-calcium alumino ferrite (C4AF), which are main constituents of OPC, were obtained. To fabricate eco-friendly light-weight cement blocks, the synthesized cement-like material were mixed with cement, water, and additional RHA and cast into blocks. The optimal compressive strength and density of the cement blocks were in comparable range with the standard light-weight concrete defined by Thai Industrial Standards Institute (TISI) and American Concrete Institute (ACI 213,2001). With jute fiber reinforcement, enhanced compressive strength of 20% was achieved, while elimination of spalling after compression test was clearly evident, implying a more ductile failure.

Utilization of Coal Combustion Waste (Fly Ash) For Geopolymer Concrete as Green Concrete

The use of Portland Cement as a paste in conventional concrete is still often the primary/favourite choice in civil engineering construction. In time, cement production will cause harm to the environment, especially in the production process, and the availability of natural raw materials in cement production will dwindle. Therefore, it is necessary to find an innovative alternative to replace cement utilization. From the test matrix that has been carried out, it can be concluded that the waste from burning coal (fly ash), can be used as a substitute for Portland cement, and also at the composition of 16 moles – the ratio of sodium silicate to sodium hydroxide of 1.5 has a strong quality much better compression than the composition when using a 100% Portland cement mixtureFrom the test matrix that has been carried out, it can be concluded that the waste from burning coal (fly ash), can be used as a substitute for Portland cement, and also at the composition of 16 moles – the ratio of sodium silicate to sodium hydroxide of 1.5 has a strong quality. much better compression than the composition when using a 100% Portland cement mixture.

Mechanical activation of diabase and its effect on the properties and microstructure of Portland cement

Many volcanic rocks with pozzolanic properties are used as additives in cement production. Although diabase is a volcanic rock, it has not been used as an additive material in cement production until now. In this study, pozzolanic reaction ability, mechanical, hydration and microstructure properties were investigated before and after mechanical activation in order to increase the usability of diabase in cement production. Firstly diabase samples were analyzed for chemical, mineralogical compositions and pozzolanic activity. The diabase was first subjected to dry grinding separately from clinker to increase the amorphous structure by decreasing its crystalline structure and mechanical activation was achieved.The pozzolanic activity of the ground diabase gradually increased depending on the grinding time. The effects of 10%, 30% and 50% addition of natural diabase by weight on the characteristics of cement pastes and cement mortars were researched. Zeolite containing cliptonolite mineral was used as a comparison material with diabase. The Blended cement specimens were tested for particle size, setting time, water demand, soundness, heat of hydration, and compressive strength. The compressive strength proportion of the cement mortar samples containing large quantities of natural diabase were lower than that of the Portland control cement at all tested ages up to 28 days, but it was a higher compressive strength than zeolite blended cements. 10%, 30% and 50% diabase blended cements and 10%, 30% and 50% zeolite blended cements give results above the Cem IV 32.5 R standards. 10%, 30% and 50% diabase blended cements have achieved high early compressive strength than zeolite blended cements. 10%, 30% and 50% diabase blended cements have achieved low final compressive strength than zeolite blended cements. In addition, diabase blended cements may produced at approximately 5% lower cost than zeolite blended cements. All results proved that diabase may be a good alternative to new generation mineral additives in producing cement.

Production System in a Collaborative Supply Chain Considering Deterioration

This research presents a mathematical model for a collaborative planning of the supply chain involving four echelons (supplier, production plants, distribution, retails, or clients). The model seeks to maximize profit (utility) when all members of the chain share information related to demand. It is developed for the aggregate consolidation of different raw materials in cement production. The novelty of the model is the consideration of products that deteriorate in the process and thus it has effect on the production times in the plant and lead time. In this supply chain, quality and compliant products and the return of deteriorated products are two flows. The considerations are lead time, inventories with shortages and excesses, production times in normal and extra days, and subcontracting, among others. A mixed integer linear programming with demand scenario analysis is used to optimize and analyze the uncertainty that is consistent with the performance of the construction sector. The model is formed considering two suppliers, two production plants, two distributors, two retailers and two end customers. Four manufacturing inputs (raw materials) are considered for the manufacture of two types of products. A case study of the cement production supply chain of Cartagena (Colombia) is illustrated. The shared benefit is generated around 5 billion pesos (COP) for all members of the chain in a period of 6 months.

Cementitious activity of iron ore tailing and its utilization in cementitious materials, bricks and concrete

A large number of iron ore tailings produced by the iron ore beneficiation industry have become a major challenge for industry owners and local government dealing with waste due to their environmental pollution, health issues and land scarcity. The best way to solve the problems of iron ore tailings is to develop large-scale utilization technologies that can consume large amounts of this waste. This paper specifically points out three directions for the use of iron ore tailings in construction and building materials, namely production of cementitious materials, preparation of bricks as well as preparation of concrete. Current research status and progress on the cementitious activity of iron ore tailings and these three directions are reviewed, and the future scope of research in this area is suggested. It is believed that iron ore tailings are consumed in large quantities, which not only solves their disposal related difficulties but also saves natural materials for these construction and building materials. From the economic point of view, it also provides economic advantages by not only producing low-cost construction and building materials, but also reducing the disposal cost of iron ore tailings.

Formation of Friedel’s salt in simulated municipal solid waste incineration bottom ash

To recycle incineration bottom ash as a raw material in cement production, it is important to reduce the chlorides in the ash. Due to Friedel’s salt, washing only is insufficient to remove the chlorides. However, limited research has examined the mechanism of Friedel’s salt formation in ash. In particular, the effect of heating in an incinerator has not been reported. In this study, we investigated the formation of Friedel’s salt using reagents. Friedel’s salt was sufficiently formed upon heating at 1350 °C for 24 h and curing for 30 days. Higher temperatures than actual incineration conditions were required to produce pure Friedel’s salt, but a small amount of chlorine was also fixed in samples closer to actual incineration conditions. XRD and TG/DTA showed that the fixed chlorine most likely contained Friedel’s salt analogues. Washing experiments conducted to understand the leachability of chlorides from samples showed that 20–69% of the fixed chlorine did not dissolve during washing. The leaching behavior of the coexisting materials suggested that some of the fixed chlorine was present not in the form of Ca4Al2O6Cl2·10H2O but in chlorides or mixtures of chlorides with Ca and Cl bound at ratios of 1:1–2, which are more easily dissolved.

Physical and Chemical Fundamentals and Technical Solutions for Recovery of Non-ferrous and Rare Metals from Industrial Wastes


 
 
 The increasing demand for zinc and a range of zinc-related metals (for example: lead; indium; tin; cadmium; and copper) in the Russian Federation cannot be satisfied by the existing production plants due to the lack of raw materials. At the same time, ferrous and non-ferrous metallurgy and the chemical industry have accumulated hundreds of millions of tons of zinc wastes (falling into the hazard categories 2 to 4), the processing of which could not only make up the raw material base, but also improve the environmental situation. In the world, over 85% of ferrous dust is recycled using the Waelz process. The Waeltz process is used for distilling separation of elements under reducing conditions. In this study, a block diagram for production of the following elements from industrial wastes is proposed: zinc, cadmium and indium in form of massive metals; zinc and indium in the form of fine powders; and clinker as a raw material for cement production. The technical and scientific details of this new process have been patented in the Russian Federation and abroad. For the first time, the following operations have been implemented with the use of large-sized Waelz kilns: vapour-oxidized Waeltz treatment of polymetallic wastes; recycling of heat from gases and solid products with generation of process fumes; and implementation of alternative flux (dolomite) and alternative fuel (petroleum coke).
 Keywords: Waelz process, industrial wastes, heat recycling, vapour-oxidized Waelz processing
 
 

Enhanced elution of chloride ions from incinerator bottom ash

Recycling of the incinerator bottom ash, which is discharged from solid waste treatment plants, is important since the landfilling capacity is limited, and if it is left untreated, it would generate a great environmental burden. Besides, the incinerator bottom ash has a similar chemical composition to that of cement and therefore it can be used as a substitute raw material in cement manufacturing. This recycling method would, in turn, reduce the consumption of natural resources, such as limestone and clay. Generally speaking, a high concentration of chloride leads to severe corrosion of steel, which can damage the reinforced concrete structure. The removal of chloride ions from the ash should, therefore, be carried out in advance to use it as a raw material for cement production. Thus, this study aims to find an effective method for eluting chloride ion from the incinerator bottom ash for recycling. One of the main findings of this work was that the residual chloride concentration in the incinerator bottom ash was reduced to 1.70 g/kg, eluting 87.78% of initial Cl concentration, when the ash was washed with an acetic acid solution (concentration: 1.5 mol/L) saturated with CO2 micro-bubbles.

Efficiency of Chemical and Biological Leaching of Copper Slag for the Recovery of Metals and Valorisation of the Leach Residue as Raw Material in Cement Production

Copper slags produced in vast quantities in smelting operations could be considered as secondary material sources instead of stockpiling them in landfills. This study investigates the recovery of valuable metals from copper slag and the valorisation of the leach residue as construction material in line with the principles of a circular economy. By taking into account that the environmental characterization of the as-received copper slag did not allow its disposal in landfills without prior treatment, chemical and biological leaching were tested for the recovery of metals. Pre-treatment with acids, namely HNO3 and H2SO4, resulted in the extraction of several target metals and the production of an almost inert waste. Despite the clearly better oxidative conditions prevailing in the bioleaching reactors, chemical leaching resulted in the higher dissolution of Cu (71% vs. 51%), Co (70% vs. 36%), and Zn (65% vs. 44%). The acid consumption was much lower during the bioleaching experiments compared to the chemical leaching. The bioleach residue was suitable for its use as supplementary cementitious material, showing a better performance than the reference sample without causing any detrimental effects to the calcium aluminate cement (CAC) quality. The complete valorisation of copper slags is expected to improve the economics of the process, by avoiding landfill costs and producing saleable products with high added value.

A Proposition of an In situ Production of a Blended Cement.

Many byproducts and waste materials with pozzolanic properties can substitute natural raw materials in cement production. Some of these waste materials like fly ash and blast furnace slag are commonly harnessed by cement industry. Others are of seldom use due to limitations of the very centralized cement production systems currently in use. In the authors opinion, it is necessary to change this system to enable efficient utilization of various waste materials that are available locally (e.g., white and red ceramics). In this study, a new partially centralized system of cement production is proposed. The adoption of a new system would significantly reduce the volume of long-distance transportation and enable utilization of numerous locally available waste materials that are currently dismissed. The last stage of production of the ready-to-use cement would take place in situ. The cement would be produced on demand and be immediately used for concrete production on-site. The research program was conducted considering the importance of the quality of cements obtained in the new way, substituting up to 12% of its mass by white ceramics. The research program was proof of concept of the proposed cement production system. It was shown that the quality of “in situ cement” does not differ from standard cements.

Oil-based mud cutting as an additional raw material in clinker production

Oil-Based Mud (OBM) cutting is a hazardous by-product generated during oil-well drilling. Its chemical composition suggests that it might be suitable as a raw material in cement manufacturing. It is rich in calcium oxide, silica, and aluminium oxide, which are the major oxides in raw materials for cement manufacturing. In this research, OBM cutting is used as a constituent of the raw meal for cement clinker production. Raw meal mixtures were prepared by mixing different ratios of raw materials increasing OBM content. The impact of the addition of OBM cutting on the resulting clinker has been investigated. The results demonstrate that OBM cutting could be recycled in the manufacturing of Portland cement clinker. Clinker prepared using OBM cutting had very similar properties to that prepared from limestone. This result could represent an opportunity for solving an environmental problem.The addition of OBM cutting lowers the calcination temperature, and increases the rate of carbonate dissociation. However, it also leads to a higher free lime in clinker, which is a result of the presence of trace elements, such as barium. Overall, its use as a raw material in cement production could provide a cost-effective, environment-friendly route for the management of OBM cutting.