scholarly journals Development of Porous Tungsten Mud Waste-based Alkali-activated Foams with Low Thermal Conductivity

2020 ◽  
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes
Keyword(s):  
Thermal Conductivity ◽  
Mining Waste ◽  
Foaming Properties ◽  
Original Material ◽  
Insulation Material ◽  
High Porosity ◽  
Low Thermal Conductivity ◽  
Aluminium Powder ◽  
Blowing Agent ◽  
Alkali Activated

Aim of this study was to produce alkali-activated foams with low thermal conductivity. Different precursors’ maximum particles sizes of 150μm, 300μm, and 500μm using a blend of 70% tungsten mining waste mud (TWM), 20% grounded waste glass (WG) and 10 % metakaolin (MK) with sodium silicate (SS) and sodium hydroxide (SH) as original material. Aluminium powder (Al) was used as a blowing agent and added first to the dry mix by changing content from 0.1g to 0.5g. Precursors and activators were mixed together to produce a homogeneous mixture, which was placed into a mould (100x200x60 mm3), and cured in the oven at 60∘C for 24 hours. The effect on foaming properties of different precursors maximum particles sizes were studied. The AAFs exhibited 28 day compressive strengths ranging from 2.28 to 16.1 MPa with the different densities from 913 to 1647 kg/m3 achieved through alteration of the foaming content. The thermal conductivity of AAFs was in the range 0.21– 0.33 W/m*K. Open celled hardened of the AAFs with 0.5g Al shows a high porosity of 58% with the mix made with 500μm. Therefore, tungsten mining waste-based alkali-activated foams shows a promise as thermal insulation material in some situations.

scholarly journals Development of Alkali-activated Foamed Lightweight Mortar Tungsten Mining Waste Mud-based Incorporating Expanded Cork

2020 ◽  
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes
Keyword(s):  
Compressive Strength ◽  
Mining Waste ◽  
Alkali Activation ◽  
Insulation Material ◽  
High Porosity ◽  
River Sand ◽  
Aluminium Powder ◽  
Al Powder ◽  
Gas Foaming ◽  
Alkali Activated

In this study, an Alkali-activation of tungsten mining waste mud (TMWM) was combined with aluminium powder (Al) as a blowing agent (gas foaming method). The synthesis of inorganic alkali-activated foamed mortar (AA-FM) and alkali-activated lightweight foamed mortar (AALW-FM) was achieved by incorporating expanded granulated cork (EGC) and one type of river sand < 2 mm. Al powder was added first to the dry mix with the mass used varying from 0.1 g to 0.5 g. Precursors and activators were included to produce a homogeneous mixture, which was placed into a mould (100x100x60 mm3), and cured in the oven at 60° C for 24 hours. The influence of two main parameters (Al powder contents and cork particles) on the AA-FM and AALW-FM properties (compressive strength, density, expansion volume and pore size distribution) were investigated. The compressive strength of the foams in the case of highly porous structures of the AALW-FM and AA-FM achieved 4.1MPa and 13.2MPa respectively, for samples with a larger amount of Al powder (0.5g). Open celled hardened of the AALW-FM and AA-FM with 0.5g Al shows a high porosity of 40% and 81% respectively. Therefore, tungsten mining waste-based alkali-activated foams shows potential as a thermal insulation material in certain situations. Keywords: Tungsten mining waste, Alkali-activated, Foamed Materials

Alkali-Activated Binder from Tungsten Mining Waste and Waste Glass

2018 ◽  
Vol 788 ◽  
pp. 45-50
Author(s):  
Gediminas Kastiukas ◽  
Xiang Ming Zhou
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Mining Waste ◽  
Waste Glass ◽  
Stabilizing Agent ◽  
Foam Stabilizer ◽  
Aluminium Powder ◽  
Organic Surfactant ◽  
Alkali Activated ◽  
Chemical Foaming

A foamed alkali-activated material (FAAM), based on tungsten mining waste (TMW) and waste glass (WG) was fabricated by using chemical foaming and pre-formed foaming methods. The compressive strength and density of the FAAM were investigated in terms of different parameters of formulation including foaming method, foam catalyzing agent and stabilizing agent. A FAAM made with aluminium powder consisted of smaller open macropores and exhibited higher compressive strength in comparison with organic surfactant counterparts which formed larger closed macropores. The final aluminium powder based FAAM reached a 7-day compressive strength in excess of 3 MPa and a density below 0.7 g/cm3. The incorporation of an appropriate amount of foam stabilizer led to a further 15% increase in compressive strength, 6% reduction in density and a thermal conductivity below 0.1 W/mK.

Freeze-drying preparation of porous diatomite ceramics with high porosity and low thermal conductivity

2020 ◽  
Vol 119 (4) ◽  
pp. 195-203
Author(s):  
Lei Han ◽  
Faliang Li ◽  
Haijun Zhang ◽  
Yuantao Pei ◽  
Longhao Dong ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Freeze Drying ◽  
High Porosity ◽  
Low Thermal Conductivity

Rigid Polyurethane Foam: A Versatile Energy Efficient Material

2016 ◽  
Vol 678 ◽  
pp. 88-98 ◽  
Author(s):  
Harpal Singh
Keyword(s):  
Thermal Conductivity ◽  
Polyurethane Foam ◽  
Weight Ratio ◽  
Building Envelope ◽  
Polymerization Reaction ◽  
Low Density ◽  
High Porosity ◽  
Rigid Polyurethane Foam ◽  
Low Thermal Conductivity ◽  
Moisture Permeability

Rigid polyurethane foam (RPUF) is typically prepared by the reaction of an isocyanate, such as methyl diphenyl diisocyanate (MDI) with a polyol blend. During the polymerization reaction, a blowing agent expands the reacting mixture. The finished product is a solid, cellular polymer with a high thermal resistance. RPUF is an outstanding material for different applications. It has many desirable properties such as low thermal conductivity, low density, low water absorption, low moisture permeability, excellent dimensional stability, high strength to weight ratio. So, it is the best insulating material for industrial buildings, cold storages, telecom and defense shelters due to low thermal conductivity, low density, low moisture permeability and high porosity. It works to reduce heating and cooling loss, improving the efficiency of the building envelope. Thus, RPUF insulation in building envelopes brings additional benefits in energy savings, resulting in lower energy bills and protecting the environment by cutting CO2 emissions.

scholarly journals Low thermal conductivity boulder with high porosity identified on C-type asteroid (162173) Ryugu

2019 ◽  
Vol 3 (11) ◽  
pp. 971-976 ◽  
Author(s):  
M. Grott ◽  
J. Knollenberg ◽  
M. Hamm ◽  
K. Ogawa ◽  
R. Jaumann ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Porosity ◽  
Low Thermal Conductivity

Experimental Investigation on the Thermal Insulation Properties of Eic-Cellulose

2014 ◽  
Vol 554 ◽  
pp. 322-326 ◽  
Author(s):  
Wuryanti Sri ◽  
Suhardjo Poertadji ◽  
Bambang Soegijono ◽  
Nasution Henry
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Thermal Insulation ◽  
Cellulose Fibers ◽  
Extraction Process ◽  
Thermal Capacity ◽  
Insulation Material ◽  
Low Thermal Conductivity ◽  
Thermal Conductivities

The material with low thermal conductivity means it has a high insulating capability for reducing heat transfer. One of materials for insulation is cellulose. This study presents a insulation material of cellulose made from reeds imperata cylindrical type with the extraction process. The extraction of cellulose fibers to form a sheet by adding 3.5% Na-CMC (Sodium Cellulose Carboksil Metyl). The process of forming the sheet uses blender for 30 minutes, 45 minutes, and 60 minutes. Furthermore, each mixture are put into the oven with temperature of 40°C for 36 hours. There are three parameters will be investigated, i.e. thermal conductivity, density and thermal capacity. The results showed that the lowest and the highest of thermal conductivities were 0.22 W/m K and a maximum 0.36 W/m K, respectively.

Research on Application of Environmental Protection Type of Blowing Agent in Polyurethane Insulation Material

2013 ◽  
Vol 368-370 ◽  
pp. 963-967
Author(s):  
Liang Yang ◽  
Shuang Zhuang ◽  
Yan Fei Chen
Keyword(s):  
Thermal Conductivity ◽  
Experimental Study ◽  
Gas Phase ◽  
Insulation Material ◽  
Environment Protection ◽  
Environment Friendly ◽  
Blowing Agent ◽  
Replacement Process ◽  
Research On Application ◽  
Insulation Performance

In this paper the environment protection type blowing agent replacement process had been briefly introduced. Experimental study had been conducted on the burning and thermal insulation performance of the traditional CFC-11 (Freon) and typical environment-friendly blowing agent, and the influence rules of density and gas phase thermal conductivity on the main performance were obtained

Analysis of Thermal Insulation Material on Building Exterior Wall

2017 ◽  
Vol 873 ◽  
pp. 153-157 ◽  
Author(s):  
Jia Jiu Diao ◽  
Xin Qin Liao ◽  
Can Fa Diao
Keyword(s):  
Thermal Conductivity ◽  
Flame Retardant ◽  
Thermal Insulation ◽  
Insulation Material ◽  
Low Thermal Conductivity ◽  
Insulation Materials ◽  
Existing Problems ◽  
Comprehensive Properties ◽  
First Choice ◽  
Insulation Performance

The use of performance, application status and existing problems of organic and inorganic thermal insulation materials, which are commonly used in the external walls of the building, are described in detail in this paper. Organic thermal insulation materials with low thermal conductivity, good thermal insulation performance, but with the flammable, low fire rating, poor safety, then it needing for flame retardant treatment. However, Inorganic thermal insulation materials with flame retardant, high fire rating, good safety performance, but poor thermal insulation properties than the organic insulation materials, so it needs to develop a low thermal conductivity of inorganic insulation materials.In the end, we pointed out that the inorganic insulation materials with low thermal conductivity and excellent comprehensive properties are expected to be the first choice for building thermal insulation materials.

Sign in / Sign up

Export Citation Format

Share Document