Water-Soluble Cr (VI) of Solidification-Cured Process and Compressive Strength of Ferrochrome Slag Complex Cement

2012 ◽  
Vol 174-177 ◽  
pp. 1096-1099
Author(s):  
Shu Xuan Wang ◽  
Ning Li ◽  
Fahong Wang ◽  
Bo Li ◽  
Yulong Li
Keyword(s):  
Compressive Strength ◽  
Chromium Content ◽  
Solidification Process ◽  
Water Soluble ◽  
National Standards ◽  
Shaking Table ◽  
Leaching Tests ◽  
Ferrochrome Slag ◽  
Maximum Content ◽  
Ferrochromium Slag

Ferrochrome slag, an essential component in stainless steel, is the by-product of ferrochromium production. The composition of the ferrochrome slag and leaching tests show that the chromium content, 3.68%, is high, although the data of leaching tests under normal conditions is very low. Leaching test was performed on an oscillating shaking table with ratio adjusted to 150r/min at L/S 8 and 80°C, during 5h. The maximum content of water-soluble Cr (Ⅵ) is 2.78μg/g (0.3475 mg/L) from ferrochromium slag under these conditions. The soluble (Cr6+ and Cr3+) content rise in the solidification process，with the increase of ferrochrome slag. The Water-soluble Cr (Cr6+ and Cr3+) under different cured times can’t be detected. The content of ferrochrome slag reached 10% is the best ratio by comprehensive consideration of water-soluble Cr (Ⅵ) of all processes, compressive strength and relevant national standards.

Study on Production of Autoclaved Aerated Concrete by Coal Gangue Fly Ash

2013 ◽  
Vol 357-360 ◽  
pp. 949-954
Author(s):  
Ye Zhang ◽  
Peng Xuan Duan ◽  
Bao Sheng Jia ◽  
Lei Li
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Drying Shrinkage ◽  
Coal Gangue ◽  
National Standards ◽  
Raw Material ◽  
Autoclaved Aerated Concrete ◽  
Binder Ratio ◽  
Material Formulation ◽  
Aerated Concrete

In this paper, the low-silicon coal gangue fly ash is used to produce autoclaved aerated concrete. The influences of water binder ratio, coal gangue fly ash content, calcareous content and conditioning agents on the compressive strength of the autoclaved aerated concrete are investigated. Optimal raw material formulation and procedure are determined for the autoclaved aerated concrete. The compressive strength and frost resistance of autoclaved aerated concrete made by the optimal raw material formulation and procedure meet with the requirements of autoclaved aerated concretes of B05 grade, and its thermal conductivity, drying shrinkage reach the requirements of the relevant national standards of China.

Experimental Study on the Detoxification of Chrome Sludge by Making Bricks

2014 ◽  
Vol 878 ◽  
pp. 708-713 ◽  
Author(s):  
Xiu Lin Yang ◽  
Wei Ye ◽  
Gao Ming Wu ◽  
Wang Sheng Chen ◽  
Jun Han
Keyword(s):  
Experimental Study ◽  
Weight Loss ◽  
Compressive Strength ◽  
Mass Fraction ◽  
Sintering Temperature ◽  
Trivalent Chromium ◽  
National Standards ◽  
Molding Pressure ◽  
Loss On Ignition ◽  
Sintering Time

In order to eliminate the toxicity of chromium sludge, hexavalent chromiumwas changed into trivalent chromium. Chromium sludge, coal and clay were used at the ratio of 0-12%:90-78%:10% to manufacture sludge bricks. Meanwhile, the influences of the sludge mass fraction, molding pressure, sintering temperature and sintering time on weight loss on ignition, chromium leaching concentration, water absorption and compressive strength of bricks were also investigated. The results indicated that the conditions for manufacturing good quality bricks was 8% sludge with 4h of sintering prepared in 20MPa molding pressure and sintered at 950°C, which can reach the national standards (HJ/T 301-2007). Furthermore, wastes were changed into resources and economical benefits were brought to the company.

Recycling of Waste Rock as a Filler to Prevent Ground Subsidence

2007 ◽  
Vol 544-545 ◽  
pp. 617-620
Author(s):  
Woo Keun Lee ◽  
Hyo Jin Ban ◽  
I Rang Im
Keyword(s):  
Compressive Strength ◽  
Structural Stability ◽  
Waste Rock ◽  
Abandoned Mines ◽  
Environmental Stability ◽  
Ground Subsidence ◽  
Leaching Tests ◽  
Leaching Test ◽  
Soil Leaching ◽  
Waste Rocks

In this study, we investigate to use waste rock as a filler for filling the cavity of abandoned mines. We discuss that waste rock can be used as a filler in the side of environmental and structural stability. Waste rocks from four mines, such as Samgi, second Yeonwha, Dongwon and Dogye, are used. Leaching tests are conducted to check the environmental stability by four methods of Soil Leaching Test, MALT, TCLP and KSLT. According to the results, Cu, Cd, Cr and As were not detected and other metals leached below 0.5 ppm. Compressive strength of waste rock and crushed waste rock are measured to evaluate the structural stability. Mixtures of crushed waste rock are used to evaluate the possibility of enhancing compressive strength. Mixture 1 is composed of 11.1% of above 13.2mm, 22.2% of 9.5-13.2mm, 33.3% of 6.7-9.5mm, 22.2% of 3.5-6.7mm and 11.1% of 2.0-3.5mm. And mixture 2 is composed of 50% of above 13.2mm and 50% of 9.5-13.2mm. Compressive of the latter was more than that of the former. Waste rock can be probably used as a filler, considering the compressive strength of commercialized filler, or 40 Kg/cm2.

scholarly journals Preparation of Lignosulfonates from Biorefinery Lignins by Sulfomethylation and Their Application as a Water Reducer for Concrete

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 841 ◽  
Author(s):  
Caoxing Huang ◽  
Junmei Ma ◽  
Weiyu Zhang ◽  
Guohong Huang ◽  
Qiang Yong
Keyword(s):  
Surface Tension ◽  
Compressive Strength ◽  
Enzymatic Hydrolysis ◽  
Zeta Potential ◽  
Water Soluble ◽  
Water Soluble Polymer ◽  
Potential Analysis ◽  
Hydrolysis Residue ◽  
Industrial Standards ◽  
Zeta Potential Analysis

Lignosulfonate (LG), a water-soluble polymer from sulfite pulping process of lignocellulosic biomass, has been commercially applied as admixture for concrete. In this work, lignosulfonates were produced from alkaline lignin (AL) and enzymatic hydrolysis residue (EHR) by sulfomethylation and these lignosulfonates as water reducers for concrete were then evaluated. Results showed that 94.9% and 68.9% of lignins in AL and EHR could be sulfonated under optimum sulfomethylation conditions, respectively. The sulfonic groups in lignosulfonates from AL (AL-LG) and EHR (EHR-LG) were 1.6 mmol/g and 1.0 mmol/g, respectively. Surface tension and zeta potential analysis indicated that both AL-LG and EHR-LG can be potentially used to as dispersant for improving the fluidity of the cement paste, similarly to commercial lignosulfonate (CM-LG). Adding 0.2 wt % of AL-LG, EHR-LG, and CM-LG in the concrete, the compressive strength (28 days) of concretes increased from 38.4 Mpa to 41.6, 42.6, and 40.9 Mpa, respectively. These findings suggest that the lignosulfonate from biorefinery lignin by sulfomethylation can meet the industrial standards as water reducers for cement admixtures.

scholarly journals Recycling Glass Cullet from Waste CRTs for the Production of High Strength Mortars

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Stefano Maschio ◽  
Gabriele Tonello ◽  
Erika Furlani
Keyword(s):  
Compressive Strength ◽  
Fine Fraction ◽  
High Strength ◽  
Leaching Tests ◽  
Glass Cullet ◽  
Glass Waste ◽  
Small Glass ◽  
Cathode Ray Tube ◽  
Overall Performance ◽  
Icp Analysis

The present paper reports on the results of some experiments dealing with the recycling of mixed cathode ray tube (CRT) glass waste in the production of high-strength mortars. Waste CRT glass cullet was previously milled, and sieved, and the only fine fraction was added to the fresh mortar in order to replace part of the natural aggregate. The addition of superplasticizer was also investigated. All hydrated materials displayed high compressive strength after curing. Samples containing CRT mixed glass showed a more rapid increase of strength with respect to the reference compositions, and materials with a superplasticizer content of 1% showed the best overall performance due to the favourable influence of the small glass particles which increase the amount of silicate hydrated produced. The induced coupled plasma (ICP) analysis made on the solutions, obtained from the leaching tests, confirmed the low elution of hazardous elements from the monolithic materials produced and consequently their possible environmental compatibility.

Preparation and Properties of a Novel Water Soluble Core Material for the Resin Transfer Molding Process

2011 ◽  
Vol 306-307 ◽  
pp. 844-847
Author(s):  
Quan Zhou Li ◽  
Xiao Qing Wu
Keyword(s):  
Compressive Strength ◽  
Resin Transfer Molding ◽  
Water Soluble ◽  
Core Material ◽  
Molding Process ◽  
Transfer Molding ◽  
The Core ◽  
Rtm Process ◽  
Binder Solution ◽  
Core Materials

A novel water soluble core material composed of alumina, quartz sand, kaolin, gypsum powder and the solution of binders was prepared. The influence of different mass concentration of Polyethylene Glycol (PEG) binder solution and sodium silicate compounded (SS) binders solution on water soluble performance and compressive strength of the core materials was investigated, respectively. The results show that the compressive strength and solubility rate of the core materials, with the concentration of 30% of SS binders solution, are 1.023MPa and 0.24g/s respectively, which is satisfied for the requirements of Resin Transfer Molding (RTM) process completely.

Preparation and Characterization of Calcium Silicate Slag Based Lightweight Wall Materials

2012 ◽  
Vol 512-515 ◽  
pp. 110-114 ◽  
Author(s):  
Lei Hou ◽  
Jin Hong Li ◽  
Ling Xin Tong
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Calcium Silicate ◽  
Raw Materials ◽  
Xrd Analysis ◽  
Potassium Feldspar ◽  
Water Soluble ◽  
Silicate Slag ◽  
Calcium Silicate Slag ◽  
Wall Materials

Potassium feldspar (KAlSi3O8) can be used to extract potassium to solve the shortage of water soluble potash resources in China, but it will produce large amount of calcium silicate slag. Resource recycling from calcium silicate slag can be realized by synthesising wall materials. In this research， calcium silicate slag based lightweight wall materials have been successfully prepared by calcium silicate hydrates (CSH), lime and fly ash through autoklave process. Furthermore, the wall materials are charactered by strength determination, X-ray diffraction (XRD) analysis, and Scanning electron microscopy (SEM) analysis. The results show that the compressive strength is mainly influenced by the lime/fly ash mass ratio (L/F), CSH content and water/solid ratio (W/S). The compressive strength of 21.1-23.9 MPa and density of 0.87-0.91 g/cm3 are achieved respectively with the L/F value of 0.82-1.00, CSH content of 70 % and W/S of 0.9. The main hydrate product of wall materials is 11Å tobermorite [Ca5(OH)2Si6O16•4H2O], which is partly formed from the phase transformation of CSH, and partly produced by the reaction among raw materials during the process of autoclaving. The tobermorite is easy formed at low L/F value and it has a contribution to the low density for its flake-like structure that make the materials porous.

scholarly journals Penggunaan Menthol untuk Bahan Konsolidan Cagar Budaya Arang

2019 ◽  
Vol 13 (1) ◽  
pp. 3-11
Author(s):  
Moh Habibi ◽  
Dimas Arif Primanda Aji ◽  
Rifqi Kurniadi Suryanto ◽  
Riyanto Prasetiya Lambang ◽  
Arif Gunawan
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Water Content ◽  
Morphological Characteristic ◽  
Solidification Process ◽  
Effect Of Temperature ◽  
Durability Testing ◽  
Site Test ◽  
Excavation Site ◽  
Shape And Size

Penelitian ini bertujuan untuk mengetahui efektivitas penggunaan menthol sebagai bahan konsolidasi sementara cagar budaya pada temuan ekskavasi yang rapuh. Pengujian yang dilakukan meliputi karakteristik morfologi menthol, penetrasi kering dan basah menthol pada ketiga jenis sampel (Arang, Bata, Batu), durabilitas konsolidasi sementara menthol pada sampel, dan kuat tekan. Hasil penelitian menunjukkan bahwa proses solidifikasi menthol dimulai pada bagian tepi dan membentuk bentukan seperti jarum (whisker). Penetrasi menthol pada sampel sangat dipengaruhi oleh bentuk dan ukuran partikel sampel serta kandungan air yang terdapat pada sampel. Untuk pengujian durabilitas, pengaruh suhu sangat besar terhadap durabilitas konsolidasi menthol. Semakin tinggi suhu lingkungan, maka semakin cepat pula proses sublimasi menthol. Hasil uji kuat tekan sangat dipengaruhi oleh ukuran partikel sampel, semakin kecil ukuran partikel sampel yang terkonsolidasi menthol, maka semakin tinggi pula nilai kuat tekan yang dihasilkan. Dari hasil penelitian ini dapat disimpulkan bahwa menthol dapat digunakan sebagai bahan konsolidan sementara cagar budaya arang. This study aims to determine the effectiveness of the use of menthol as temporary consolidant for fragile heritage findings on the excavation site. Test includes morphological characteristic of menthol, dray and wet penetration of menthol to three type of sample (charcoal, stone, and brick), durability, and compressive strength. The results show that the menthol solidification process starts at the edges and forms a shape like whiskers. Menthol penetration is strongly influenced by the shape and size of the sample and also water content in the samples. For durability testing, the effect of temperature is very significant on the durability of menthol consolidation. The higher the temperature, the faster the menthol sublimation process will be. Whereas for compressive strength is highly influenced by particle size of the consolidated sample, the smaller consolidated sample the higher compressive strength produced. From this study it can be concluded that menthol can be used as a temporary consolidant material for the fragile heritage findings.

scholarly journals Influence on Compressive Strength and Drying Shrinkage of Concrete with Urea-Water Soluble Sulfur Admixture

2016 ◽  
Vol 31 (5) ◽  
pp. 74-81
Author(s):  
Jae Kyu Park ◽  
Sang Hoon Han ◽  
Ki Nam Hong ◽  
Yong In Cho ◽  
Yuzhe Chai
Keyword(s):  
Compressive Strength ◽  
Drying Shrinkage ◽  
Water Soluble

Improving the anti-washout property of calcium phosphate cement by introducing konjac glucomannan/κ-carrageenan blend

2019 ◽  
Vol 33 (8) ◽  
pp. 1094-1104 ◽  
Author(s):  
Guowen Qian ◽  
Xingmei Li ◽  
Fupo He ◽  
Jiandong Ye
Keyword(s):  
Compressive Strength ◽  
Calcium Phosphate ◽  
Calcium Phosphate Cement ◽  
Setting Time ◽  
Konjac Glucomannan ◽  
Water Soluble ◽  
Mouse Bone Marrow ◽  
Human Cancellous Bone ◽  
Marrow Mesenchymal Stem Cells

Anti-washout calcium phosphate cement (CPC) was prepared by dissolving water-soluble konjac glucomannan (KGM) and κ-carrageenan (KC) blend in the cement liquid. The anti-washout property, setting time, compressive strength and in vitro cytocompatibility of the CPC modified with KGM/KC blend were evaluated. The results indicated that the CPC pastes modified with KGM/KC blend exhibited excellent anti-washout property. The addition of KGM/KC blend shortened the setting time and increased the injectability of CPC. Although the introduction of KGM/KC blend reduced the compressive strength of CPC, the compressive strength still surpassed that of human cancellous bone. The optimal KGM/KC mass ratio was 2:8, with which the modified cement exhibited the most efficient washout resistance and the highest compressive strength. The introduction of KGM/KC blend obviously promoted the proliferation of mouse bone marrow mesenchymal stem cells. This anti-washout CPC modified by KGM/KC blend with excellent in vitro cytocompatibility will have good prospects for application in bone defect repair.

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