scholarly journals Evaluation of the mechanical properties of wood-derived charcoal briquettes for use as a reductant

2021 ◽  
Vol 121 (5) ◽  
Author(s):  
N.W. Makgobelele ◽  
R.K.K. Mbaya ◽  
J.R. Bunt ◽  
N.T. Leokaoke ◽  
H.W.J.P. Neomagus
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Polyvinyl Alcohol ◽  
Abrasion Resistance ◽  
Water Resistance ◽  
Resistance Index ◽  
Ash Content ◽  
Curing Time ◽  
Atmospheric Conditions ◽  
Future Work

SYNOPSIS Silicon Smelters consumes more than 80000 t/a of wood-derived charcoal as carbonaceous reductant in the production of silicon metal. More than 10% of this material is discarded as fines (<6 mm) generated due to abrasion during processing. Charcoal fine residues (<650 μm) and polyvinyl alcohol (PVA) binder were used in this study to produce mechanically strong charcoal briquettes for metallurgical application as carbonaceous reductant. The PVA binder was added in mass percentages of 1, 3, and 5 wt% to the charcoal fines. The compressive strength, abrasion resistance index (ARI), drop shatter resistance (SRI), and water resistance index (WRI) were measured as functions of curing for up to 7 days under atmospheric conditions, and the results compared with metallurgical grade coarse charcoal. The ash content of the produced briquettes was found to be high (6.6-8.0%) compared with the coarse charcoal (1-3%). The 3 and 5 wt% PVA-bound briquettes were found to be the strongest, with compressive strengths of 40 and 115 kg/cm2 respectively, with WRI values of 75 and 73% respectively. The produced briquettes were found to have lower ARI and SRI values compared to the coarse charcoal. Future work should include beneficiation of the fine charcoal discards prior to briquetting, and an increase in binder addition to above 6 wt% to improve the ARI and SRIn. Keywords: wood charcoal, fines, briquettes, reductant, polyvinyl alcohol binder, compressive strength, water resistance, curing time.

Influences of Emulsion on Water Resistance of Vitrified Micro Bubbles Thermal Insulation Material

2013 ◽  
Vol 662 ◽  
pp. 433-436
Author(s):  
Jiang Zhu ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Polyvinyl Alcohol ◽  
Stearic Acid ◽  
Thermal Insulation ◽  
Water Resistance ◽  
Insulation Material ◽  
Molding Process ◽  
Thermal Insulation Material ◽  
Improve Water Resistance ◽  
Softening Coefficient

Vitrified micro bubbles thermal insulation material was made of vitrified micro bubbles, cement, fly ash, gypsum and sodium silicate, by molding process. VAE emulsion and stearic acid-polyvinyl alcohol emulsion were added to improve water resistance of the material. Mixed with 10% VAE emulsion and 5% stearic acid-polyvinyl alcohol emulsion, properties of the material are followed as: flexural strength 0.64MPa, compressive strength 1.35MPa, softening coefficient 0.71 and 2h volumetric water absorption 6.9%.

scholarly journals Valorization of briquettes fuel using Pinus spp. sawdust from five regions of Mexico

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 2249-2263
Author(s):  
María Alejandra Ramírez-Ramírez ◽  
Artemio Carrillo-Parra ◽  
Faustino Ruíz-Aquino ◽  
Luis Fernando Pintor-Ibarra ◽  
Nicolás González-Ortega ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Impact Resistance ◽  
Resistance Index ◽  
Calorific Value ◽  
Volatile Matter ◽  
Ash Content ◽  
Fixed Carbon ◽  
Volumetric Expansion ◽  
Pinus Spp ◽  
The Impact

This research characterized briquettes made with Pinus spp. sawdust without the use of additives. For this purpose, 19 samples of sawdust from different wood industries located in five states of the Mexican Republic were used. The densification process was carried out in a vertical hydraulic piston laboratory briquette machine. The briquettes were made with 40 g of sawdust, at 50 °C, 20 kPa and pressing for 5 min. The results obtained varied as follows: moisture content (4.1% to 7.2%), density (813.9 to 1,014.4 kg/m3), volumetric expansion (7.4% to 37.3%), compressive strength (4.9 to 40.8 N/mm), impact resistance index (46.7% to 200%), ash (0.1% to 1.1%), volatile matter (82.9% to 90.7%), fixed carbon (8.9% to 16.4%), and calorific value (20.5 to 22.8 MJ/kg). The density of the briquettes was within the “acceptable” classification (800 to 1,200 kg/m3). It was observed that, the higher the density, the lower the volumetric expansion, the higher the compressive strength, and the higher the impact resistance index. According to the ash content, the briquettes could achieve international quality. Due to high volatile matter values, rapid combustion of the briquettes with little generation of toxic smoke would be expected. Fixed carbon and calorific value results were acceptable.

scholarly journals Thermal and Mechanical Properties of Cement Mortar Composite Containing Recycled Expanded Glass Aggregate and Nano Titanium Dioxide

2020 ◽  
Vol 10 (7) ◽  
pp. 2246 ◽  
Author(s):  
Ali Yousefi ◽  
Waiching Tang ◽  
Mehrnoush Khavarian ◽  
Cheng Fang ◽  
Shanyong Wang
Keyword(s):  
Heat Transfer ◽  
Mechanical Properties ◽  
Compressive Strength ◽  
Titanium Dioxide ◽  
Energy Consumption ◽  
Transfer Rate ◽  
Water Resistance ◽  
Cement Mortar ◽  
Residential Buildings ◽  
Nano Titanium Dioxide

One of the growing concerns in the construction industry is energy consumption and energy efficiency in residential buildings. Moreover, management of non-degradable solid glass wastes is becoming a critical issue worldwide. Accordingly, incorporation of recycled expanded glass aggregates (EGA) as a substitution for natural fine aggregate in cement composites would be a sustainable solution in terms of energy consumption in the buildings and waste management. This experimental research aims to investigate the effects of EGA on fresh and hardened properties and thermal insulating performance of cement mortar. To enhance the mechanical properties and water resistance of the EGA-mortar, nano titanium dioxide (nTiO2) was used as nanofillers. The results showed an increase in workability and water absorption of the EGA-mortar. In addition, a significant decrease in bulk density and compressive strength observed by incorporating EGA into the cement mortar. The EGA-mortar exhibited a low heat transfer rate and excellent thermal insulation property. Furthermore, inclusion of nTiO2 increased compressive strength and water resistance of EGA-mortar, however, their heat transfer rate was increased. The results demonstrated that EGA-mortar can be integrated into the building envelop or non-load bearing elements such as wall partition as a thermal resistance to reduce the energy consumption in residential buildings.

Laboratory Experimental Research on Mix Ratio Test of Cement Soil

2013 ◽  
Vol 438-439 ◽  
pp. 197-201
Author(s):  
Xian Hua Yao ◽  
Peng Li ◽  
Jun Feng Guan
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Cement Content ◽  
Ratio Test ◽  
Curing Time ◽  
Curing Conditions ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Cement Soil

Based on the generalization and analysis of laboratory experimental results on mix ratio, the effects of various factors such as cement content, water-cement ratio, curing time, curing conditions and types of cement on the mechanical properties of unconfined compressive strength of cement soil are presented. Results show that the unconfined compressive strength of cement soil increases with the growing curing time, and it is greatly affected by the cement content, water-cement ratio, cement types and curing time, while the effect of curing conditions is weak with a cement content of more than 10%. Moreover, the stress-strain of the cement soil responds with the cement content and curing time, increasing curing time and cement content makes the cement soil to be harder and brittle, and leads to a larger Young's modulus.

Research about the Effect of Polypropylene Fiber on Mechanical Properties of Curing Sludge

2011 ◽  
Vol 250-253 ◽  
pp. 788-794
Author(s):  
Shu Lin Zhan ◽  
Shu Sen Gao ◽  
Jun Ying Lai
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Shear Strength ◽  
Water Content ◽  
Unconfined Compressive Strength ◽  
Polypropylene Fiber ◽  
Physical And Mechanical Properties ◽  
Curing Time ◽  
Strength Tests ◽  
Different Content

In order to study the influence of modified polypropylene (PP) fiber on the physical and mechanical properties of curing sludge, the same amount of cement and different content of polypropylene fiber were mixed into the sludge. Unconfined compressive strength tests, water content tests and shear strength tests were carried out on different specimens with different curing time. The results show that the sludge curing effect is markedly improved by the addition of the polypropylene fiber. As to the curing sludge with the same curing time, when the content of the polypropylene fiber increases, the unconfined compressive strength and the cohesive strength greatly increase, and the internal frictional angle decreases.

Fly Ash Particle Reinforced AA6061 Composites Produced by Recycling of Aluminum Chips and Fly Ash Particles

2011 ◽  
Vol 324 ◽  
pp. 38-41
Author(s):  
Recep Vatansever ◽  
Harun Mindivan ◽  
E.S. Kayali
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Compressive Strength ◽  
Aluminum Alloy ◽  
Fly Ash ◽  
Hot Extrusion ◽  
Ash Content ◽  
Aluminum Powders ◽  
Aluminum Chips ◽  
Recycled Composites

In this work, the re-use of aluminum AA6061 chips and fly ash particles by solid-state processes (cryomilling, cold compaction and hot extrusion) is presented. The process was performed in following steps: comminuting of chips, cryomilling of comminuted chips, aluminum powders and fly ash particles, cold pressing-hot extrusion approach without sintering step. Comparative analysis of the recycled composites with fine and coarse granulated chips was focused on mechanical properties and correlated to microstructural features. The density and electrical conductivity of the recycled composites are lower than those of the unreinforced aluminum alloy due to the presence of fly ash particles. Regarding mechanical properties, the recycled composites with coarse granulated chips showed higher hardness and compressive strength than the recycled composites with fine granulated chips, but the compressive strength of the recycled composites with coarse granulated chips decreased with the increase of fly ash content.

scholarly journals Effects of Sulfur Curing Systems on Mechanical Properties of NR/SBR Rubber Blends

2019 ◽  
Author(s):  
Ruogu Tang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Abrasion Resistance ◽  
Relative Volume ◽  
Curing Time ◽  
High Modulus ◽  
Elongation At Break ◽  
Tear Strength ◽  
Rubber Blends ◽  
Curing Systems

<div>A series of NR/SBR vulcanizates were prepared by conventional vulcanization (CV), effective vulcanization (EV) and semi-effective vulcanization (SEV) respectively basing on each formulation and optimum curing time. We examined the mechanical properties of NR/SBR vulcanizates including tensile strength, tear strength, elongation at break, modulus, Shore A hardnessand and relative volume abrasion. The results indicated that NR/SBR vulcanizates prepared in different systems differed in mechanical properties. Vulcanizates prepared via CV showed higher tensile and tear strength; vulcanizates prepared via EV had high modulus and hardness, and vulcanizates prepared via SEV performed high abrasion resistance. </div>

scholarly journals Influence of Solid Content, Cement/Tailings Ratio, and Curing Time on Rheology and Strength of Cemented Tailings Backfill

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 922
Author(s):  
Jiajian Li ◽  
Erol Yilmaz ◽  
Shuai Cao
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Rheological Properties ◽  
Flow Rate ◽  
Unconfined Compressive Strength ◽  
Solid Content ◽  
Similar Type ◽  
Curing Time ◽  
Flow Process ◽  
Resistance Loss

Understanding the flow process of cemented tailings backfill (CTB) is important for successful pumping into underground stopes. This study examines the effects of solid content (SC), cement/tailings (c/t) ratio, and curing time (CT) on rheological and mechanical properties of CTB mixes. The slurry concentration of the mixes was 65, 67, and 69 wt. %, with c/t ratios ranging from 1:4 to 1:20. Unconfined compressive strength (UCS) tests were performed on hardened CTB mixes after curing 3, 7, and 28 days. The rheological properties of CTB slurries are mainly related to SC. The yield stress and viscosity of fresh mixes increase with increasing SC, but the pipeline resistance loss (PRL) also increases with increasing SC. According to the analysis of variance, the SC and flow rate are the most significant parameters which greatly affect the PRL performance. The c/t and CT parameters are the most significant parameters for affecting the shrinkage rate. The findings offer a reference for theoretical optimization for mine filling systems of similar type.

scholarly journals The Potential of Ladle Slag and Electric Arc Furnace Slag use in Synthesizing Alkali Activated Materials; the Influence of Curing on Mechanical Properties

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1173 ◽  
Author(s):  
Češnovar ◽  
Traven ◽  
Horvat ◽  
Ducman
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Room Temperature ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Alkali Activation ◽  
Arc Furnace ◽  
Curing Time ◽  
Promising Alternative ◽  
Alkali Activated

Alkali activation is studied as a potential technology to produce a group of high performance building materials from industrial residues such as metallurgical slag. Namely, slags containing aluminate and silicate form a useful solid material when activated by an alkaline solution. The alkali-activated (AA) slag-based materials are promising alternative products for civil engineering sector and industrial purposes. In the present study the locally available electric arc furnace steel slag (Slag A) and the ladle furnace basic slag (Slag R) from different metallurgical industries in Slovenia were selected for alkali activation because of promising amorphous Al/Si rich content. Different mixtures of selected precursors were prepared in the Slag A/Slag R ratios 1/0, 3/1, 1/1, 1/3 and 0/1 and further activated with potassium silicate using an activator to slag ratio of 1:2 in order to select the optimal composition with respect to their mechanical properties. Bending strength of investigated samples ranged between 4 and 18 MPa, whereas compressive strength varied between 30 and 60 MPa. The optimal mixture (Slag A/Slag R = 1/1) was further used to study strength development under the influence of different curing temperatures at room temperature (R. T.), and in a heat-chamber at 50, 70 and 90 °C, and the effects of curing time for 1, 3, 7 and 28 days was furthermore studied. The influence of curing time at room temperature on the mechanical strength at an early age was found to be nearly linear. Further, it was shown that specimens cured at 70 °C for 3 days attained almost identical (bending/compressive) strength to those cured at room temperature for 28 days. Additionally, microstructure evaluation of input materials and samples cured under different conditions was performed by means of XRD, FTIR, SEM and mercury intrusion porosimetry (MIP).

Mechanical Properties of Reactive Powder Concrete Containing Fly Ash under Different Curing Regimes

2014 ◽  
Vol 597 ◽  
pp. 320-323 ◽  
Author(s):  
De Hong Wang ◽  
Yan Zhong Ju ◽  
Wen Zhong Zheng
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Ash Content ◽  
Reactive Powder Concrete ◽  
Steam Curing ◽  
Cement Ratio ◽  
Reactive Powder ◽  
Curing Regimes

Mechanical properties of reactive powder concrete (RPC) containing fly ash were investigated under different curing regimes (standard and steam curing) in this study. The experimental results indicate that, flexural strength of RPC increased considerably after steam curing, compared to the standard curing. Steam curing had no significant effect on compressive strength of RPC. Increasing the fly ash content improved the flexural strength of RPC under all curing regimes considerably. The compressive strength reached a maximum (103.8MPa) when the fly to ash and cement ratio is 0.3.

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