Research on the Preparation of Unburned Ceramic Particles from Recycled Sand Tailings by Disc Granulation Method

Ceramics particles of Al2O3 and SiC (mean diameter:'40-770μm) were coated with fine metal particles of Al, Ni, Co, Mo and W (mean diameter: 5-10μm) by the agglomeration coating technique in which ceramics particles containing polyethylene glycol as binder were mixed with metal particles in a rotating cylinder and heated above the melting point of polyethylene glycol so that metal particles were fixed on the surface of ceramics particles by the molten binder. The quantity of metal coating reached a maximum of about 60 vol%. Coarser ceramics particles attained a larger quantity of metal coating. The addition of Al-stearate to metal particles was effective to disperse metal particles and increase the surface coverage of the coating.

Water treatment ceramic particles were prepared using dewatered life sludge in Huainan No.1 Sewage treatment plant and power plant fly ash as main materials and clay as the bond. Through the L9 (43) orthogonal test, we obtained the best conditions of the preparing process. The product can be used as water treatment packing ceramic particles and simulated adsorption experiment with the wastewater including Pb2 + was conducted. The results indicate that ceramic particles (used as wastewater treatment filler) bibulous rate is 25.0%, the loose density is 690kg/m3, the particle density is 1240kg/m3, specific surface area is 5.997m2/g, the compressive strength is 9.40MPa and the adsorptive performance is excellent. The toxic metal leaching experimental result shows that the concentration of toxic heavy metals in leaching solution is in the range of GB specification and the performance of product is stable which will not cause second pollution.

Preparation and characterization of magnetic γ-Al2O3 ceramic nanocomposite particles with variable Fe3O4 content and modification with epoxide functional polymer

Adding ceramic particles in the plate hammer is an effective method to increase the wear resistance of the hammer. The liquid phase method is based on the “with the flow of mixed liquid forging composite preparation of ZTA ceramic particle reinforced high chromium cast iron hammer. Preparation method for this system is using CFD simulation analysis the particles distribution of flow mixing and filling process. Taking the 30% volume fraction of ZTA ceramic composite of high chromium cast iron hammer as example, by changing the speed of liquid metal viscosity to control and make reasonable predictions of particles distribution before solidification.

Composite adsorbents were prepared by encapsulating ceramic hydroxyapatite particles (CHT Type I) within inert agarose beads using an emulsion method as stationary phases for the removal of small protein and nucleic acid impurities from large proteins and bioparticles in a flow-through mode. The composite particles were prepared with 6% and 10% agarose and contain 35% and 25% (v/v) CHT, respectively, with effective pore radii of 15.1 and 8.8 nm. The functional properties were studied using yeast RNA, bovine serum albumin (BSA), thyroglobulin (Tg), IgM, and 30 and 50 nm silica nanoparticles (NP) as models. The RNA and BSA adsorption capacities are smaller than for unencapsulated CHT on a bead volume basis but comparable when normalized by the volume of CHT particles in the composite beads attaining values between 30 and 40 mg/mL. Confocal laser scanning microscopy shows that, while RNA and BSA have complete access to the encapsulated CHT particles, Tg, IgM, and the NPs are largely excluded. RNA and BSA breakthrough experiments in laboratory-scale columns at a 5-min residence time show RNA and BSA binding capacities comparable to those measured in a batch mode with either single component feeds or with feed mixtures containing 30 nm NPs.

To meet the requirements of high strength of tungsten (W) based alloys at high temperature applied in the aerospace field, the preparation and formation of Hf-related ceramic particles in W were studied. It is found that the HfO2 phase with a size of about 500 nm was observed at the grain boundary in both W-0.26 wt.% HfC and W-0.25 wt.% HfH2-0.125 wt.% C systems. Further study of phase stability and thermodynamic properties of Hf(W)-O(C) compounds reveals that the HfO2 phase possesses the most stability of all the Hf-related compounds, and the oxidation of Hf is preferred to the carbonization. It is predicted that more stability of W base metal, higher temperature, and higher carbon concentration can reduce the formation of HfO2 while promoting the formation of the HfC particle phase.

Influence of synergistic strengthening effect of B4C and TiC on tribological behavior of copper-based powder metallurgy

The wettability between ceramic particles and metal play an important role in fabrication of ceramic particles reinforced metal matrix composites(PRMMCs). In present paper, Al2O3 particles were coated with nickel by chemical plating to modify the preparation and properties of Al2O3 particles reinforced steel matrix composites. Using the Al2O3 particles treated by chemical nickel-plating, Al2O3 particles reinforced steel matrix composites were fabricated by powder metallurgy process(PM). And the wear resistance of the composites was investigated. The results show that: the nickel coating can fully and tightly cover on the surface of Al2O3 particles, and the nickel coating thickness is uniform about 2~3 micron; The nickel coating can effectively improve the uniform distribution of Al2O3 particles in the composites. And the treated Al2O3 particles can be tightly bonded with steel matrix,which improve the wear resistance of composites. The wear resistance of composites reinforced treated and untreated Al2O3 particles each is 2.5 and 1.6 times of Hadfield steel.

One of the methods for improving metal-ceramic interface and suppression of agglomeration is the formation of a monolayer electroless coating on the particles. Investigations indicated that Ni-B monolayers should be first formed to develop in the next process an electroless Ni–P coating with the morphology of cauliflower. It was possible to produce a Ni-B layer on WC particles when a bath was heated at a temperature of 95 °C by using sodium borohydride and an appropriate stabilizer. Following this process, the Ni–P electroless coating was deposited on WC particles at 85 °C. In this way, two layers of electroless coating of Ni–B/Ni–P on the WC ceramic particles without using the surface activator were produced successfully. The coating morphology and surface analysis were performed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The results showed that only the degreasing with acetone as a surface preparation of ceramic particles is sufficient to make a Ni–P or Ni–B coating. Electroless Ni–B coating with appropriate adhesion to the surface produces an acceptable surface for the electroless Ni – P coating formation.

Fundamental study was carried out to evaluate and optimize fine powder of iron ore granulation. In this study, the conditions of particle preparation and mechanism of granulation were discussed. As a conclusion of this study, for both fine and coarse iron ore sample, the optimum conditions for pellet growth, were defined by saturation degree value of approximately 0.9–1.0. Furthermore, it was found that wet pellet agglomerates were formed as a result of compaction and tumbling action under the condition of saturation degree S from S≧1 in particle preparation stage to S=0.9 (0.85) at final granulation stage, and that Stokes deformation number at that time indicates to determine optimal granulation condition. When introducing new granulation method to commercial agglomeration process for fine powder of iron ore, saturation degree and Stokes deformation number show a suitable operating point of new system to attain required quality of granulation.

Preparation of ceramic fine particles by means of planetary bead milling

The transmutation concept of minor actinide (MA)–bearing nuclear fuel plays an important role in managing highly radioactive waste. A facile route combining the sol-gel process and microfluidic technology was presented to fabricate Ce/Eu oxide microspheres as a surrogate for plutonium-based MA-bearing nuclear fuel. Uniform Ce/Eu oxide microspheres with a varied Eu content (7.90%, 13.00%, and 17.56%) were successfully fabricated using the co-sol-gel method. The prepared microspheres had a narrow size distribution (coefficient of variance < 2%) and excellent sphericity (dmax/dmin < 1.09). The Ce and Eu elements were shown to have a relatively homogeneous distribution in the microspheres through energy dispersive X-ray spectroscopy mapping images. Thermal behavior analysis, microstructure observation, and crystalline structure analysis were conducted systematically. The X-ray diffraction patterns showed one cubic lattice structure for all of the samples.

Preparation of Ceramic Hollow Particles by Using Vapor-Phase Deposition

流動層造粒装置による主薬をべースとしたコーティング用核粒子の調製

Ceramic particle reinforced iron-based alloys have been widely used in aerospace, land transportation and other aspects, so it has attracted tremendous attention. Aiming at the preparation and interfacial reaction of ceramic particle reinforced iron-based alloys, the preparation methods for interfacial reactions, reinforcement selection and design of ceramic particle reinforced iron-based alloys are introduced in this paper. Combined with the recent studies on ceramic particle reinforced iron-based alloys, this paper focuses on the ceramic particle reinforced iron-based interface and strengthening models/mechanisms, based on existing research, prospects for further ceramic particle reinforced iron-based alloys were studied.