During the process of oil and gas exploration and development, cementing operation is the key factor to ensure oil well productivity release, and the performance of additives is directly related to the success or failure of cementing. In this study, the polymer retarder PID-1 was synthesized by aqueous solution polymerization, the chemical structure, thermal stability and micro-structure of PID-1 were studied by infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. Moreover, the retarding effect and mechanism of PID-1 was analyzed based on low field nuclear magnetic resonance analysis, adiabatic calorimetry and scanning electron microscopy. Then, the polymer/organic compound high temperature retarder PID-2 was constructed by adding organic compound PN with well retarding property, and then the retarding effect, thickening property, temperature and dosage sensitivity of PID-2 were investigated. Combined with porosity evolution, type and content of hydration products, the internal mechanism of retarder PID-2 on early mechanical strength development of cement slurry system was revealed.
{"title":"Construction, Properties and Mechanism of Polymer/Organic Compound High Temperature Retarder for Oil and Gas Exploration and Development","authors":"Jin‐hua Huo, Xing Zhang, Ruizhi Zhang, Bai-song Yu","doi":"10.1680/jadcr.21.00047","DOIUrl":"https://doi.org/10.1680/jadcr.21.00047","url":null,"abstract":"During the process of oil and gas exploration and development, cementing operation is the key factor to ensure oil well productivity release, and the performance of additives is directly related to the success or failure of cementing. In this study, the polymer retarder PID-1 was synthesized by aqueous solution polymerization, the chemical structure, thermal stability and micro-structure of PID-1 were studied by infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. Moreover, the retarding effect and mechanism of PID-1 was analyzed based on low field nuclear magnetic resonance analysis, adiabatic calorimetry and scanning electron microscopy. Then, the polymer/organic compound high temperature retarder PID-2 was constructed by adding organic compound PN with well retarding property, and then the retarding effect, thickening property, temperature and dosage sensitivity of PID-2 were investigated. Combined with porosity evolution, type and content of hydration products, the internal mechanism of retarder PID-2 on early mechanical strength development of cement slurry system was revealed.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45277727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hybrid Engineering Cementitious Composite (HECC) combines different fibers’ advantages, but based on the current research, the mechanical behaviors exposed to high temperature of HECC mixed with Polyvinyl Alcohol fiber, steel fiber, and basalt fiber still need to be much more studied. HECC's mechanical properties can be obtained from tensile and compression experiments. The mechanical properties investigation of PVA-ECC(mixed with only PVA fiber), BF-ECC(mixed with only BF), SF-ECC(mixed with only SF), HECC-PB(mixed with PVA and BF), and HECC-PS (mixed with PVA and SF) adding 65%, 70%, and 78% fly ash individually were conducted at room temperature. The mechanical properties experiment after high temperature of the above five materials mixed with 70% fly ash were conducted, which was heated to 200°C, 400°C, 600°C, and cooled to room temperature. According to specimen's appearance change, strength change, mass loss, ductility loss and failure form, HECC-PS has the best tensile and compressive behaviors after exposing high temperature, which can be as plastering layer on masonry structure surface to ensure the safety of masonry at high-temperature environment.
{"title":"Mechanics behaviors study of Hybrid fiber reinforced cementitious composites exposed high temperatures","authors":"Gao Shuling, Zhang Jiayao, Zhu Yanping, Wang Zhe","doi":"10.1680/jadcr.21.00188","DOIUrl":"https://doi.org/10.1680/jadcr.21.00188","url":null,"abstract":"Hybrid Engineering Cementitious Composite (HECC) combines different fibers’ advantages, but based on the current research, the mechanical behaviors exposed to high temperature of HECC mixed with Polyvinyl Alcohol fiber, steel fiber, and basalt fiber still need to be much more studied. HECC's mechanical properties can be obtained from tensile and compression experiments. The mechanical properties investigation of PVA-ECC(mixed with only PVA fiber), BF-ECC(mixed with only BF), SF-ECC(mixed with only SF), HECC-PB(mixed with PVA and BF), and HECC-PS (mixed with PVA and SF) adding 65%, 70%, and 78% fly ash individually were conducted at room temperature. The mechanical properties experiment after high temperature of the above five materials mixed with 70% fly ash were conducted, which was heated to 200°C, 400°C, 600°C, and cooled to room temperature. According to specimen's appearance change, strength change, mass loss, ductility loss and failure form, HECC-PS has the best tensile and compressive behaviors after exposing high temperature, which can be as plastering layer on masonry structure surface to ensure the safety of masonry at high-temperature environment.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48064788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In practically fly ash and slag have been widely used in cement production. The effect of alkali sulfates in clinker on hydration and hardening of cement blended with fly ash and slag was studied. The results of hydration heat evolution, hydrates analysis and mechanical properties indicate arcanite (K2SO4), thenardite (Na2SO4), aphthitalite (3K2SO4·Na2SO4, K3NS4) and Ca-langbeinite (K2SO4·2CaSO4, KC2S3) in clinker could activate the pozzolanic activity of fly ash and slag facilitating the appearance of the 2nd hydration peak at initial hydration period and promote the hydration and hardening properties of blended cement. The adverse effects of alkali sulfates in clinker are alleviated with the addition of fly ash and slag, which can be attributed to the dilution effect and filler effect of SCMs as well as the effect of alkali sulfates activating fly ash and slag. K2SO4, Na2SO4 and K3NS4 present a better activating effect on mortar with slag than fly ash mortar to increase compressive strength and reduce drying shrinkage while the content of alkali sulfates is less than 0.6% Na2Oeq.
{"title":"Effect of alkali sulfates in clinker on hydration and hardening properties of cement incorporating SCMs","authors":"Ying Ma, J. Qian","doi":"10.1680/jadcr.21.00110","DOIUrl":"https://doi.org/10.1680/jadcr.21.00110","url":null,"abstract":"In practically fly ash and slag have been widely used in cement production. The effect of alkali sulfates in clinker on hydration and hardening of cement blended with fly ash and slag was studied. The results of hydration heat evolution, hydrates analysis and mechanical properties indicate arcanite (K2SO4), thenardite (Na2SO4), aphthitalite (3K2SO4·Na2SO4, K3NS4) and Ca-langbeinite (K2SO4·2CaSO4, KC2S3) in clinker could activate the pozzolanic activity of fly ash and slag facilitating the appearance of the 2nd hydration peak at initial hydration period and promote the hydration and hardening properties of blended cement. The adverse effects of alkali sulfates in clinker are alleviated with the addition of fly ash and slag, which can be attributed to the dilution effect and filler effect of SCMs as well as the effect of alkali sulfates activating fly ash and slag. K2SO4, Na2SO4 and K3NS4 present a better activating effect on mortar with slag than fly ash mortar to increase compressive strength and reduce drying shrinkage while the content of alkali sulfates is less than 0.6% Na2Oeq.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42380224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Na Zhang, Hong-fa Yu, Hai-yan Ma, M. Ba, Haoxia Ma
Adding mineral admixtures is a green, economic and effective method to improve the properties of magnesium oxysulfate (MOS) cement. Based on modified MOS cement by low calcium fly ash (L-FA), high calcium fly ash (H-FA) and granulated blast furnace slag (G-BS), the effects of L-FA, H-FA and G-BS and SF double mixing on the properties of MOS cement were studied by characterizing the compressive strength, water resistance, hydration heat, hydration products and micropore structure characteristics, and the modification mechanism of mineral admixtures was discussed. The results show that the L-FA, G-BS and SF double mixing can further optimize the hydration product composition and micropore structure of MOS cement, thus improving its compressive strength and water resistance. The hydration reaction rate of MOS cement and 5·1·7 phase content in the hydration products is increased by H-FA and SF double mixing, but the micropore structure is not further optimized, which is the reason why the water resistance of MOS cement with H-FA and SF is not improved. The research results enrich the basic theory of mineral admixtures to improve the properties of MOS cement and provides theoretical guidance for its practical application.
{"title":"Effects of compound mineral admixtures on properties of magnesium oxysulfate cement","authors":"Na Zhang, Hong-fa Yu, Hai-yan Ma, M. Ba, Haoxia Ma","doi":"10.1680/jadcr.22.00006","DOIUrl":"https://doi.org/10.1680/jadcr.22.00006","url":null,"abstract":"Adding mineral admixtures is a green, economic and effective method to improve the properties of magnesium oxysulfate (MOS) cement. Based on modified MOS cement by low calcium fly ash (L-FA), high calcium fly ash (H-FA) and granulated blast furnace slag (G-BS), the effects of L-FA, H-FA and G-BS and SF double mixing on the properties of MOS cement were studied by characterizing the compressive strength, water resistance, hydration heat, hydration products and micropore structure characteristics, and the modification mechanism of mineral admixtures was discussed. The results show that the L-FA, G-BS and SF double mixing can further optimize the hydration product composition and micropore structure of MOS cement, thus improving its compressive strength and water resistance. The hydration reaction rate of MOS cement and 5·1·7 phase content in the hydration products is increased by H-FA and SF double mixing, but the micropore structure is not further optimized, which is the reason why the water resistance of MOS cement with H-FA and SF is not improved. The research results enrich the basic theory of mineral admixtures to improve the properties of MOS cement and provides theoretical guidance for its practical application.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45092210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alkali-activated cements utilising fly ash can be a low carbon alternative to Portland cement. However, fly ash alkali-activated cements require elevated temperature curing and has cost plus environmental implications due to the use of strong alkali solutions. Unclassified fly ash, silica fume, calcium hydroxide and sodium carbonate were used to develop novel one-part fly ash alkali-activated cements. Cured at ambient conditions, the developed cements gained compressive strength up to 11.0 and 44.2 MPa at 3 and 28 days respectively. Microstructural investigations revealed that cation exchange reaction between the activators was the key element in microstructural and strength development of the cements. The developed novel fly ash alkali-activated cements have at least 50% lower impact on global warming than highly blended Portland cements.
{"title":"Novel one-part fly ash alkali-activated cements for ambient applications","authors":"Oscar Tarique, M. Kovtun","doi":"10.1680/jadcr.21.00144","DOIUrl":"https://doi.org/10.1680/jadcr.21.00144","url":null,"abstract":"Alkali-activated cements utilising fly ash can be a low carbon alternative to Portland cement. However, fly ash alkali-activated cements require elevated temperature curing and has cost plus environmental implications due to the use of strong alkali solutions. Unclassified fly ash, silica fume, calcium hydroxide and sodium carbonate were used to develop novel one-part fly ash alkali-activated cements. Cured at ambient conditions, the developed cements gained compressive strength up to 11.0 and 44.2 MPa at 3 and 28 days respectively. Microstructural investigations revealed that cation exchange reaction between the activators was the key element in microstructural and strength development of the cements. The developed novel fly ash alkali-activated cements have at least 50% lower impact on global warming than highly blended Portland cements.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49600969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study evaluates the performance of green mortar incorporating an eco-cement made from various proportions of rice husk ash (RHA), ground granulated blast furnace slag (GGBFS), and circulation fluidized bed combustion fly ash (CFA). Different RHA contents of 15 wt%, 30 wt%, and 45 wt% were used to replace GGBFS (by weight), respectively, and these mixtures were activated by 15 wt%, 20 wt%, and 25 wt% CFA by the total weight of GGBFS and RHA. Engineering properties of the mortars were examined by compressive strength, splitting tensile strength, water absorption, porosity, and dynamic Young's modulus, while the sulfate resistance and scanning electron micrographs analysis were conducted to evaluate the durability and microstructure of the mortar samples. Test results demonstrated that the content of the RHA and CFA strongly impacted the properties of these samples. Based on the obtained results, the samples with 20 wt% CFA and < 30 wt% RHA showed the best performance at later ages. Also, CFA decreased the sulfate resistance of the green mortar samples, while RHA increased sulfate resistance and significantly reduced thermal conductivity. Furthermore, the scanning electron micrographs exhibited the amorphous gels and the ettringite crystal-like phase, promoting a denser microstructure of the mortars.
{"title":"Performance evaluation of a green mortar developed from a ternary eco-cement of industrial solid wastes","authors":"D. Vo, C. Hwang, Trong‐Phuoc Huynh","doi":"10.1680/jadcr.21.00102","DOIUrl":"https://doi.org/10.1680/jadcr.21.00102","url":null,"abstract":"This study evaluates the performance of green mortar incorporating an eco-cement made from various proportions of rice husk ash (RHA), ground granulated blast furnace slag (GGBFS), and circulation fluidized bed combustion fly ash (CFA). Different RHA contents of 15 wt%, 30 wt%, and 45 wt% were used to replace GGBFS (by weight), respectively, and these mixtures were activated by 15 wt%, 20 wt%, and 25 wt% CFA by the total weight of GGBFS and RHA. Engineering properties of the mortars were examined by compressive strength, splitting tensile strength, water absorption, porosity, and dynamic Young's modulus, while the sulfate resistance and scanning electron micrographs analysis were conducted to evaluate the durability and microstructure of the mortar samples. Test results demonstrated that the content of the RHA and CFA strongly impacted the properties of these samples. Based on the obtained results, the samples with 20 wt% CFA and < 30 wt% RHA showed the best performance at later ages. Also, CFA decreased the sulfate resistance of the green mortar samples, while RHA increased sulfate resistance and significantly reduced thermal conductivity. Furthermore, the scanning electron micrographs exhibited the amorphous gels and the ettringite crystal-like phase, promoting a denser microstructure of the mortars.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43530724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As an industrial solid waste of limestone quarry, limestone powder (LP) is often used in cement-based materials to reduce cost and carbon dioxide emission. It is well-known that the synergistic effect between LP and alumina-rich supplementary cementitious materials (SCMs) influences the properties of cement-based materials. To quantitative study the synergistic effect, the hydration heat, hydration products and porosity of cement pastes with different binders were investigated. Test results showed that the synergistic effect between limestone powder and fly ash (FA) or slag (S) improved the hydration degree and increased the total hydration heat of cement pastes. When fly ash and slag were incorporated, the 3d consumed CaCO3 content increased from 2.0 wt.% to 4 wt.%, and the 180d consumed CaCO3 content increased from 2.4 wt.% to 9.3 wt.% and 11.8 wt.%, respectively. The incorporation of fly ash or slag also increased the diffraction peak of carboaluminate, which indicated more carboaluminate were formed. The synergistic effect between limestone powder and supplementary cementitious materials refines the pore structure and reduces the porosity of cement pastes. The calculated synergistic effect between limestone powder and fly ash or slag increased the density of cement pastes by 1.04% or1.41%, respectively, and it correspondingly improved the compressive strength of cement pastes.
{"title":"A Quantitative Study on the Synergistic Effect between Limestone Powder and Supplementary Cementitious Materials","authors":"Dehui Wang, Huangfei Jia","doi":"10.1680/jadcr.21.00027","DOIUrl":"https://doi.org/10.1680/jadcr.21.00027","url":null,"abstract":"As an industrial solid waste of limestone quarry, limestone powder (LP) is often used in cement-based materials to reduce cost and carbon dioxide emission. It is well-known that the synergistic effect between LP and alumina-rich supplementary cementitious materials (SCMs) influences the properties of cement-based materials. To quantitative study the synergistic effect, the hydration heat, hydration products and porosity of cement pastes with different binders were investigated. Test results showed that the synergistic effect between limestone powder and fly ash (FA) or slag (S) improved the hydration degree and increased the total hydration heat of cement pastes. When fly ash and slag were incorporated, the 3d consumed CaCO3 content increased from 2.0 wt.% to 4 wt.%, and the 180d consumed CaCO3 content increased from 2.4 wt.% to 9.3 wt.% and 11.8 wt.%, respectively. The incorporation of fly ash or slag also increased the diffraction peak of carboaluminate, which indicated more carboaluminate were formed. The synergistic effect between limestone powder and supplementary cementitious materials refines the pore structure and reduces the porosity of cement pastes. The calculated synergistic effect between limestone powder and fly ash or slag increased the density of cement pastes by 1.04% or1.41%, respectively, and it correspondingly improved the compressive strength of cement pastes.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44920929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuanda Wang, Xuefang Wang, Y. Lou, F. Gao, Wenda Wu
One-part geopolymers are a low-carbon alternative to Portland cement, and are more suitable in engineering applications compared to two-part geopolymers. In this paper, the effects of mechanical activation on the properties of one-part fly ash/slag-based geopolymer paste and the mechanism of the pozzolanic reaction are studied. Simple mixing was established as the control group, and the effect of mechanical activation on the macroscopic properties of geopolymers was studied through testing compressive strength, fluidity and setting time. The effect of mechanical activation on the pozzolanic reaction of geopolymers was assessed using isothermal calorimetry, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TG-DTG). The results showed that the 28-day compressive strength of geopolymer formed by mechanical activation was 26% higher than that by simple mixing. Workability and fluidity were also enhanced. The reactivity of the precursor was improved by mechanical activation, particularly with fly ash. Mechanically activated fly ash experienced a pozzolanic reaction within 7 days, while undisturbed fly ash produced pozzolanic activity after 14–28 days. The implications of these results in terms of the influence of mechanical activation on pozzolanic activity are subsequently discussed. Highlights · Mechanical activation improved the setting time, fluidity, and compressive strength of one-part fly ash/slag-based geopolymer. · Mechanical activation significantly improved the pozzolanic activity of fly ash. · Mechanical activation lessened the carbonization of one-part fly ash/slag-based geopolymer.
{"title":"Effect of mechanical activation on reaction mechanism of one-part fly ash/slag-based geopolymer","authors":"Yuanda Wang, Xuefang Wang, Y. Lou, F. Gao, Wenda Wu","doi":"10.1680/jadcr.21.00033","DOIUrl":"https://doi.org/10.1680/jadcr.21.00033","url":null,"abstract":"One-part geopolymers are a low-carbon alternative to Portland cement, and are more suitable in engineering applications compared to two-part geopolymers. In this paper, the effects of mechanical activation on the properties of one-part fly ash/slag-based geopolymer paste and the mechanism of the pozzolanic reaction are studied. Simple mixing was established as the control group, and the effect of mechanical activation on the macroscopic properties of geopolymers was studied through testing compressive strength, fluidity and setting time. The effect of mechanical activation on the pozzolanic reaction of geopolymers was assessed using isothermal calorimetry, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TG-DTG). The results showed that the 28-day compressive strength of geopolymer formed by mechanical activation was 26% higher than that by simple mixing. Workability and fluidity were also enhanced. The reactivity of the precursor was improved by mechanical activation, particularly with fly ash. Mechanically activated fly ash experienced a pozzolanic reaction within 7 days, while undisturbed fly ash produced pozzolanic activity after 14–28 days. The implications of these results in terms of the influence of mechanical activation on pozzolanic activity are subsequently discussed. Highlights · Mechanical activation improved the setting time, fluidity, and compressive strength of one-part fly ash/slag-based geopolymer. · Mechanical activation significantly improved the pozzolanic activity of fly ash. · Mechanical activation lessened the carbonization of one-part fly ash/slag-based geopolymer.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45674528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The phosphate mining industry produces large amounts of tailings. Rational utilization of phosphorus tailings (PT) is of great significance for the full utilization of resources and environmental protection. In this study, PT was used as part of raw materials to prepare white Portland cement clinker (WPCC). XRD, SEM-EDS, TG-DSC, and FTIR, etc. were used to study the effect of PT on mineral composition, ionic solid solution and strength of WPCC. he results showed as follows: PT as part of the raw material of WPCC could significantly improve the burnability of raw materials, increase the content of liquid phase, and promote the formation of minerals; The addition of PT stabilized the α’-C2S crystal and promoted the C3S crystal in the clinker tend to change from T-type to M-type; There was no significant effect for PT's addition on the decomposition temperature of CaCO3, the appearance temperature of liquid phase and the formation temperature of C3S; Compared with the control group, when PT content was 2.5%, WPCC had the highest strength. its 3d strength increased by 46.86% and 28d strength increased by 82.59%.
{"title":"Effect of flotation phosphorus tailings on the microstructure and macroscopical strength of white Portland cement","authors":"Zhen Wang, Lei Huang, Pinghua Lian, Shaowen Huang","doi":"10.1680/jadcr.21.00086","DOIUrl":"https://doi.org/10.1680/jadcr.21.00086","url":null,"abstract":"The phosphate mining industry produces large amounts of tailings. Rational utilization of phosphorus tailings (PT) is of great significance for the full utilization of resources and environmental protection. In this study, PT was used as part of raw materials to prepare white Portland cement clinker (WPCC). XRD, SEM-EDS, TG-DSC, and FTIR, etc. were used to study the effect of PT on mineral composition, ionic solid solution and strength of WPCC. he results showed as follows: PT as part of the raw material of WPCC could significantly improve the burnability of raw materials, increase the content of liquid phase, and promote the formation of minerals; The addition of PT stabilized the α’-C2S crystal and promoted the C3S crystal in the clinker tend to change from T-type to M-type; There was no significant effect for PT's addition on the decomposition temperature of CaCO3, the appearance temperature of liquid phase and the formation temperature of C3S; Compared with the control group, when PT content was 2.5%, WPCC had the highest strength. its 3d strength increased by 46.86% and 28d strength increased by 82.59%.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48949831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to solve the problem of large-scale utilization of magnesium resources in salt lake, low-cost magnesium oxysulfate (MOS) cement was prepared by using magnesia residue as raw material to produce light burning magnesia after washing and calcining. The effects of calcination temperature on the properties of calcined products and the phase and microstructure of MOS cement prepared from the calcined products were studied. The results showed that Mg(OH)2 had been completely decomposing when the calcination temperature was higher than 500°C and calcination time was 2 h. As the calcination temperature reaches 500°C and continues to rise, the activity of MgO gets higher and the crystal size gets larger. It can be seen from the microstructure and XRD that the high temperature is beneficial to the growth of needlestick phase 5Mg(OH)2·MgSO4·7H2O (Phase 5) of the prepared MOS. High calcination temperature results in high porosity.
{"title":"Effects of calcination process of Salt Lake magnesium slag on properties of magnesium oxysulfide cement","authors":"Xiuquan Liu, J. Wen, Chenggong Chang, Weixin Zheng, Qiyuan Liu, Xueying Xiao, Jin-mei Dong","doi":"10.1680/jadcr.21.00145","DOIUrl":"https://doi.org/10.1680/jadcr.21.00145","url":null,"abstract":"In order to solve the problem of large-scale utilization of magnesium resources in salt lake, low-cost magnesium oxysulfate (MOS) cement was prepared by using magnesia residue as raw material to produce light burning magnesia after washing and calcining. The effects of calcination temperature on the properties of calcined products and the phase and microstructure of MOS cement prepared from the calcined products were studied. The results showed that Mg(OH)2 had been completely decomposing when the calcination temperature was higher than 500°C and calcination time was 2 h. As the calcination temperature reaches 500°C and continues to rise, the activity of MgO gets higher and the crystal size gets larger. It can be seen from the microstructure and XRD that the high temperature is beneficial to the growth of needlestick phase 5Mg(OH)2·MgSO4·7H2O (Phase 5) of the prepared MOS. High calcination temperature results in high porosity.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44078479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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