Liu Jianbo

Bio: Liu Jianbo is an academic researcher from Wuhan University of Science and Technology. The author has contributed to research in topics: Sawdust & Pellets. The author has an hindex of 3, co-authored 3 publications receiving 17 citations.

Micro-Porosity and Properties of Light-Weight Insulation Refractories Based on Calcined Flint Clay

Abstract: In this study, light-weight insulation materials were prepared with calcined flint clay as the main material and sawdust was infused by sols as a pore forming agent. Micro-porosity and properties of the prepared insulation materials were investigated and were found to have better comprehensive properties. Apparent porosity, bulk density and cold crushing strength of the compositions containing 40 wt% calcined flint clay, fired at 1400°C for 3 h, were found to be 71%, 0.85 g.cm–3 and 2.65 MPa, respectively. Thermal conductivity of the material was 0.133 W.m–1.K –1 at 300°C. When sawdust was soaked by 0 wt% sol, microstructure of the materials showed irregular pores. When sawdust was infused with 7 wt% alumina sol, the micropores were wrapped with larger pore. Meanwhile, the original pore was refined, and cold crushing strength and thermal conductivity were also optimized. When the sawdust was soaked in alumina sol, the cold crushing strength increased to 3.3 MPa and the thermal conductivity decreas...

Light-weight and heat-isolation mullite bricks and preparation method thereof

Abstract: The invention particularly relates to light-weight and heat-isolation mullite bricks and a preparation method thereof. The technical scheme is that the light-weight and heat-isolation mullite bricks are prepared from the following raw materials in percentage by weight: 40 to 48 percent of flint clay, 14 to 38 percent of kyanite, 6 to 16 percent of clay and 14 to 24 percent of alpha-Al2O3 fine powder, wherein a bonding agent is 15 to 20 percent by weight of the raw materials, and a pore-forming agent is 45 to 60 percent by weight of the raw materials. The preparation method comprises the following steps of firstly mixing the alpha-Al2O3 fine powder with the pore-forming agent, and carrying out wet grinding for 8 to 10 hours to obtain homogenized mud; uniformly stirring the homogenized mud, the flint clay, the kyanite, the clay and the bonding agent; carrying out aging, forming and baking; and preserving the heat at 1,325 to 1,450 DEG C for 3 to 5 hours to obtain the light-weight and heat-isolation mullite bricks. The light-weight and heat-isolation mullite bricks and the preparation method thereof have the advantages of saving resources, being simple in process, and being environmentally-friendly; and the prepared light-weight and heat-isolation mullite bricks are high in heat stability, low in heat conduction coefficient, low in volume density, low in after-burning linear shrinkage ratio, high in compression strength and good in heat insulation and isolation effect.

High-strength microporous calcium hexaluminate lightweight aggregate and preparation method thereof

Abstract: The invention relates to high-strength microporous calcium hexaluminate lightweight aggregate and a preparation method thereof. The technical scheme is that the preparation method comprises steps as follows: 85wt%-95wt% of fine hydrated alumina powder and 5wt%-15wt% of nano-CaCO3 are taken as raw materials, water accounting for 100wt%-500wt% of the raw materials is added, ball milling is performed for 150-480 min, and a muddy mixture is obtained; the muddy mixture is dried at the temperature of 70-120 DEG C and ground into powder, then an organic plasticizer accounting for 0.01wt%-0.20wt% of the raw materials is added to the powder and mixed uniformly with the powder, a mixture is placed into a pelletizer, and spherical pellets are produced; then the spherical pellets are dried at the temperature of 90-110 DEG C and subjected to heat preservation at the temperature of 1,400-1,700 DEG C for 1-7 h, and the high-strength microporous calcium hexaluminate lightweight aggregate is obtained. The preparation method has the characteristics that energy saving and environmental protection are realized, the process is simple and sintering is easy; the prepared high-strength microporous calcium hexaluminate lightweight aggregate has the advantages of high purity, stable performance, small pore size and uniform distribution, high strength, low thermal conductivity, low volume density and low bulk density.

Effect of Lanthanum Zirconate on High Temperature Resistance of Thermal Barrier Coatings

Abstract: Thermal barrier coatings (TBCs) typically have low thermal conductivity and high resistance to oxidation at elevated temperatures. TBCs are used to protect the turbine blades of aircraft engines op...

New insight into treatment of foundry waste: porous insulating refractory based on waste foundry sand via a sacrificial fugitive route

Abstract: Waste foundry sand (WFS) accounts for the largest percentage of environmental wastes in the foundry industry and shows an alarming and continuous increase. The treatment of WFS has been investigated previously and mainly as building materials. In this work, the applicability of leaching hazardous WFS in the manufacture of porous thermal insulation material is investigated. Thermodynamic calculation and experimental investigation are performed to evaluate the crystalline composition, microstructure characteristic, strength, and heat-insulating performance, and leaching behavior. In addition to WFS, raw materials include plastic clay, kyanite, and sawdust. High addition of WFS promotes the densification and leads to the remarkable increase in compressive strength. Samples compose of 75 wt% WFS, 15 wt% plastic clay, 10 wt% kyanite, and extra 20 wt% sawdust have a maximum strength of 0.92 MPa and thermal conductivity of 0.11 W (m K)−1 at 200 °C. According to toxicity characteristic leaching procedure analysis, the target metal concentrations in porous material based on WFS are within the US EPA limits, which proves the environmentally friendly application.

Preparation method of light-weight high-strength calcium hexaluminate fire resistant material

Abstract: The invention provides a preparation method of a light-weight high-strength calcium hexaluminate fire resistant material. The method is characterized by comprising the following steps that (1) 38-60%of calcarea carbonica raw material and 40-62% of aluminium hydroxide are mixed by weight and mixed with, by weight, 80-120% of water, 0.02-0.05% of dispersing agent and 1-4% of binding agent, and ball-milling is carried out for 3-5 hours to obtain a mixed slurry; (2) spray granulation is carried out on the mixed slurry to obtain spherical fine particles; (3) the spherical fine particles are calcined at 1000-1200 DEG C to obtain light-weight porous beads; (4) 15-30% of light-weight porous beads and 70-85% of aluminium oxide raw material are mixed by weight and mixed with 2-6% of binding agent by weight, after stirring is uniform, compression molding is carried out under 10-30 MPa, and calcination is carried out for 6-8 hours at 1600-1700 DEG C to obtain the light-weight high-strength calcium hexaluminate fire resistant material.

Heat-insulating building material and preparation method thereof

Abstract: The invention relates to a heat-insulating building material. The heat-insulating building material comprises the following components in parts by weight: 30-36 parts of flint clay, 17-20 parts of bauxite, 8-11 parts of carbon black, 4-8 parts of tsavorite, 21-25 parts of kaolin, 8-13 parts of Muyu stone, 15-19 parts of oil shale, 12-18 parts of quartz, 7-12 parts of pottery clay, 6-9 parts of diatomite, 7-10 parts of pearl mica, 9-13 parts of silicon dioxide and 13-17 parts of expanded perlite. The invention further relates to a preparation method of the heat-insulating building material. Thepreparation method comprises the following steps: taking the raw materials in parts by weight, adding the raw materials into a ball mill according to a ratio of balls, water and the raw materials of2:0.8:1, and grinding until residues on a sieve with the fineness of 250 meshes account for 0.2-0.3%; and adding 0.5-0.7 part of CMC, uniformly mixing, removing iron, sieving by using a 300-mesh sieve, dewatering and drying, sending into a furnace, and calcinating at high temperature. The prepared heat-insulating building material has the heat conductivity coefficient being lower than 0.063 w/m.k,is light in self weight, strong in heat radiation resistance, low in water absorption and high in stability, and has good economic benefits and energy-saving, environment-friendly and heat-insulatingeffects.

A Novel Method of Preparing Hexagonal Ordered Porous Alumina and Analyzing the Formation Mechanism

Abstract: In this paper, a novel method of preparing porous alumina with alumina powder and boric acid is firstly proposed and experimented, and its mechanism of the fabricating process is also investigated....