Enrichment of Phosphorus from Iron Ore to Dicalcium-silicate Phase by Partial Reduction

Layered Double Hydroxide (LDH) is ionic clay that is characterized by the union of metal cations and OH- hydroxides. LDH composites exhibit considerably high releasing and recharging capacity and have applications as bioactive cements. They can be prepared by direct co-precipitation of metal salts at controlled pH. The preparation is carried out from an acid solution of Zn (NO3)2.6H2O, Al (NO3)3.9H2O and a basic solution of Na2CO3 and NaOH, with a Zn/Al ratio = 3, the pH is stabilized between 9 and 9.5 at a constant temperature of 45°C. The objective of this study is to incorporate Zinc and Aluminum elements at different percentages in dicalcium silicate phase to produce C2S phase incorporating LDH composite. The characterizations of the developed phases by XRD and SEM indicate the formation of stoichiometric LDH phases Zn6Al2(OH)16CO3.4H2O and non-stoichiometric Zn0.61Al0.39 (OH)2(CO3)0.195.xH2O, the incorporation of Zn in the belitic C2S phase and not Al. The obtained micrographs by SEM(EDAX) analysis show new morphology of the stabilized composite.

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Precipitation Behavior of V-Enrichment Mineral in Steelmaking Slag Bearing Vanadium Modified by SiO2

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.295-298.1729 ◽

2013 ◽

Vol 295-298 ◽

pp. 1729-1734

Author(s):

Liu Shun Wu ◽

Yun Zhou ◽

Yuan Chi Dong

Keyword(s):

Calcium Silicate ◽

Converter Slag ◽

Dicalcium Silicate ◽

Experimental Results ◽

Steelmaking Slag ◽

Precipitation Behavior ◽

Silicate Phase ◽

Rich Phase ◽

Addition Amount

In order to concentrate vanadium in converter slag bearing vanadium, the effect of SiO2 on behavior of vanadium in the process of enriching was studied. Experimental results show that, during cooling, dicalcium silicate containing vanadium and phosphorus precipitate first from original slag. For original with 7% SiO2, most of vanadium dissolves in calcium silicate phase. However, the proportion of dicalcium silicate is big. For slag modified by 12% SiO2, during cooling, two vanadium-rich minerals precipitate firstly, i.e. Ca3(V,P)2O8(30-33%V2O5) and Ca3(V,P)2O8•nCa2SiO4 (14-31%V2O5), then 3CaO•2SiO2 (2-4%V2O5) generates. With addition amount of SiO2 increasing, the proportion of 3CaO•2SiO2 decreases gradually, and the content of vanadium in vanadium-rich phase increases gradually. So appropriate SiO2 addition can suppress the precipitation of Ca2SiO4 and Ca3•Si2O7, and promote the generation of vanadium-rich phase.

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Influence of Sijiaying Iron Ore on the Structure of Sinter

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.284-286.1311 ◽

2011 ◽

Vol 284-286 ◽

pp. 1311-1314

Author(s):

Li Na Liu ◽

Xiu Li Han ◽

Chang Cun Li ◽

Jie Li

Keyword(s):

Iron Ore ◽

Optical Microscope ◽

Dicalcium Silicate ◽

Metal Phase ◽

Calcium Ferrite

Microstructure and quality of sinter of Sijiaying iron ore were studied systematically by means of optical microscope. Results show that the content of sinter of different ratio of Sijiaying iron ore are simple, the content of metal phase are magnetite and hematite, binding phases mainly are calcium ferrite and dicalcium silicate, and the contents of calcium ferrite are higher. The whole microstructure of sinter is uniform, which is interweaving corroded structure. The magnetites are major tiny allotriomorphic crystal. The shape of calcium ferrite is needle-like. The quality of sinter can meet the production request when the proportions of Sijiaying iron ore are from 50% to 100%.

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New calcium silicate phase in hydrothermally treated γ-dicalcium silicate–quartz mixtures

Nature ◽

10.1038/248581a0 ◽

1974 ◽

Vol 248 (5449) ◽

pp. 581-582 ◽

Cited By ~ 5

Author(s):

A. BEZJAK ◽

I. JELENIĆ ◽

J. JERNEJČIČ

Keyword(s):

Calcium Silicate ◽

Dicalcium Silicate ◽

Silicate Phase

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Experimental Study on the Preparation of Cementing Materials by Direct Reduction Coupling of a Hematite-Carbon Base

Metals ◽

10.3390/met10081086 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1086 ◽

Cited By ~ 1

Author(s):

Ruimeng Shi ◽

Junxue Zhao ◽

Xiaoming Li ◽

Chong Zou ◽

Yaru Cui ◽

...

Keyword(s):

Experimental Study ◽

Iron Ore ◽

Raw Materials ◽

Direct Reduction ◽

Tricalcium Silicate ◽

Dicalcium Silicate ◽

Raw Material ◽

Experimental Conditions ◽

Reduction Of Iron ◽

Direct Reduction Of Iron

The reduction of iron in hematite and process coupling of cementing material generated from gangue components are explored in this paper, and a technical proposal for preparing directly reduced iron and cementing materials considering the processes of energy and material flows is proposed. An experimental study preparing cementing materials, such as tricalcium silicate and dicalcium silicate, by roasting the components, was performed. In this study, hematite was used as the raw material and powdered carbon was added, as the reducing agent, with CaO; at the same time, the gangue components of iron ore were used as the principal raw materials for the process of directly reduced iron preparation by direct reduction of iron ore. The FactSage software package was used to perform thermodynamic calculations of the reduction of iron and its influence on the formation of tricalcium silicate and dicalcium silicate. The feasibility of the direct reduction of iron to elemental iron and preparation of cementing materials by roasting of gangue components under the studied thermodynamic conditions was discussed. Different temperature control strategies were used to verify the reaction coupling test. The results showed that zero-valent iron could be produced by roasting and reducing hematite under certain experimental conditions, and cementing materials, such as tricalcium silicate and dicalcium silicate, could be produced simultaneously by reacting the gangue components with CaO. Fe2O3 exerted an adverse effect on the formation of tricalcium silicate, and sufficient reduction of the iron was a precondition for the formation and stability of tricalcium silicate.

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Mine Tailing as Alternative to Clay for Producing Belite Cement Clinker

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.2704 ◽

2013 ◽

Vol 726-731 ◽

pp. 2704-2713 ◽

Cited By ~ 4

Author(s):

Yong Chao Zheng ◽

Qing Li ◽

Yan Jun Liu

Keyword(s):

Iron Ore ◽

High Strength ◽

Calcium Sulphate ◽

Dicalcium Silicate ◽

National Standard ◽

Cement Clinker ◽

Utilization Rate ◽

Strength Development ◽

Iron Ore Tailing ◽

Belite Cement

In this study, with iron ore tailing as an alternative to clay, three belite cement clinker samples were prepared in a muffle furnace at 1400°C for 10, 20 and 30 minutes respectively. And calcium sulphate and calcium fluoride were used as composite mineralizer with attempt to decrease clinkering temperature and improve hydraulic activity of dicalcium silicate. QXRD analysis shows that the major mineral components of the clinker are dicalcium silicate,account for over 80% of clinker, and trace amount of tricalcium silicate and ferrite. Scanning Electron Microscope (SEM) analysis indicates that mineral grains were growing with the prolonged soaking duration. EDS analysis identified that C2S has a Ca/Si ratio varying from 2.07 to 2.32. And XPS analysis shows substantial amount of S and F atoms indented on clinker surface. Using 4×4×16cm mortar specimen, the mechanical strength of belite cement with 5% gypsum addition was investigated based on Chinese National Standard. The testing results show that three belite clinkers give very promising strength development at early ages, and very high strength gain was achieved at 28 days. In addition, this belite cement has a Lime Saturation Factor (LSF) of 0.76, which make it have potential for significant CO2 emission reduction. Also, more than 35% iron ore tailing was exhausted for producing unit ton of belite cement clinker. High utilization rate leads to not only mineral waste exhaustion, also environmental improvement.

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Hydration of iron–phosphorus doped dicalcium silicate phase

Materials Chemistry and Physics ◽

10.1016/j.matchemphys.2005.04.047 ◽

2005 ◽

Vol 94 (2-3) ◽

pp. 190-194 ◽

Cited By ~ 11

Author(s):

My.Y. Benarchid ◽

A. Diouri ◽

A. Boukhari ◽

J. Aride ◽

I. Elkhadiri

Keyword(s):

Dicalcium Silicate ◽

Silicate Phase ◽

Phosphorus Doped

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Elaboration and thermal study of iron–phosphorus-substituted dicalcium silicate phase

Cement and Concrete Research ◽

10.1016/j.cemconres.2004.01.030 ◽

2004 ◽

Vol 34 (10) ◽

pp. 1873-1879 ◽

Cited By ~ 23

Author(s):

My.Y. Benarchid ◽

A. Diouri ◽

A. Boukhari ◽

J. Aride ◽

J. Rogez ◽

...

Keyword(s):

Thermal Study ◽

Dicalcium Silicate ◽

Silicate Phase

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Hydration Activity and Carbonation Characteristics of Dicalcium Silicate in Steel Slag: A Review

Metals ◽

10.3390/met11101580 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1580

Author(s):

Hao Na ◽

Yajun Wang ◽

Xi Zhang ◽

Junguo Li ◽

Yanan Zeng ◽

...

Keyword(s):

Carbon Dioxide ◽

Chemical Activation ◽

Carbon Dioxide Sequestration ◽

Steel Slag ◽

Dicalcium Silicate ◽

Precipitation Process ◽

Silicate Phase ◽

Cement Production ◽

Crystal Forms ◽

Carbonation Process

Dicalcium silicate is one of the main mineral phases of steel slag. Ascribed to the characteristics of hydration and carbonation, the application of slag in cement production and carbon dioxide sequestration has been confirmed as feasible. In the current study, the precipitation process of the dicalcium silicate phase in steel slag was discussed. Meanwhile, the study put emphasis on the influence of different crystal forms of dicalcium silicate on the hydration activity and carbonation characteristics of steel slag. It indicates that most of the dicalcium silicate phase in steel slag is the γ phase with the weakest hydration activity. The hydration activity of γ-C2S is improved to a certain extent by means of mechanical, high temperature, and chemical activation. However, the carbonation activity of γ-C2S is about two times higher than that of β-C2S. Direct and indirect carbonation can effectively capture carbon dioxide. This paper also summarizes the research status of the application of steel slag in cement production and carbon dioxide sequestration. Further development of the potential of dicalcium silicate hydration activity and simplifying the carbonation process are important focuses for the future.

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