Abstract: The paper presents an overview of the present status and the perspectives for use of
structured catalysts in the power generation, transport and environmental sectors. In particular
catalytic combustion of natural gas for the production of energy in gas turbines, abatement of NOx
from mobile and stationary sources under lean and stoichiometric conditions, removal of VOC from
industrial effluents and soot combustion in the exhaust gases of vehicles are discussed.
Abstract: Hydroxyapatite (HA) microspheres of diameter <70 μm have been synthesized by solgel
processing. The starting sols were prepared by ultrasonic mixing of concentrated solutions of
calcium acetate (1.7M) with 85% H3PO4, followed by emulsification in dehydrated 2-ethyl-1-
hexanol. Drops of emulsion were solidified by extraction of water with this solvent. The final
thermal treatment was a 2 h soaking in air at 900°C. Properties such as hydraulic resistance and
sedimentation rate, which are important for application in ion-exchangers, were superior for our
prepared microspheres in comparison with irregularly shaped commercial HA. Adsorption of the
following metals was investigated: U, Zn, Fe, Cu, Ni, Co, Cd, Pb, Mn, Al, Cr, As, Sb, Bi and
Mo. Retention was ≈100% for of all the metals studied when pH > 3–4. On average, ≈1/20 moles
of metal reacted with 1 mole of HA. Adsorbed metals could be desorbed with efficiencies of
60–90%. In addition, nuclear-waste-saturated beds of HA could be transformed to insoluble
ceramics by thermal treatment. The cost of producing HA microspheres was estimated to be
comparable to current prices of irregularly shaped commercial hydroxyapatite powders. For
radioactive contaminants such as U, for which resorption need not be considered, porous
monoliths were produced by use of industrial reagents. The retention capacity was determined to
be 30 mg of U per 1 mg of monolith.
Abstract: It has been required to change the industrial production processes to low waste emission ones from a
view point of environmental issue. In the production of aluminum building materials, large amount
of sludge is emitted as industrial waste. If we can change the waste to valuable products, we can
respond to the request. Synthesis technology of kaolinitic particles from various starting raw
materials had been established at National Industrial Research Institute of Nagoya (NIRIN, present:
AIST Chubu). Hydro-thermal treatment is applied to the technology and obtained particles show
various shapes such as plate, shell and so on. Collaborative research work between NIRIN and YKK
corporation to develop high performance alumina powder form aluminum sludge, a by-product from
surface treatment process in the manufacturing of aluminum building materials, had been done by
using the fruits from the research project on kaolinite synthesis at NIRIN. As the result, high
performance platy alumina powder was developed by using hydro-thermal synthesis technology.
Abstract: The use of industrial waste materials as additives in the manufacture of ceramic
products has been attracting a growing interest from researchers in recent years and is
becoming common practice. The continued depletion of natural resources throws a new light
on the potential use of some industrial wastes and natural sub-products as full-fledged
alternative ceramic raw materials. This work describes the research carried out on the low
temperature manufacturing of alumina bodies using, as additive, granite reject as-produced by
an ornamental stone processing industry that saws granite stones into blocks and slabs in Rio
Grande do Norte, Brazil. This reject is produced in significant amounts and is discarded in
sedimentation lagoons, landfill areas or simply thrown in rivers, resulting in environmental
pollution. Samples containing up to 30 wt% granite reject and 5 wt% manganese oxide
(constant) were uniaxially pressed and sintered in air in an electric furnace (1150-1350 °C, for
1 hour). Sintered test pieces were characterized by X-ray diffraction, apparent density, open
porosity and flexural strength. The results showed that the addition of granite reject and
manganese oxide enables low temperature sintering and remarkably improves the cold
mechanical properties of the alumina body.
Abstract: This work describes the studies carried out with various industrial wastes and natural byproducts
based on the SiO2-Al2O3-CaO system, aimed at extruding ceramic products of industrial
interest. Four waste materials were selected and characterised, namely, (i) Al-rich anodising sludge
(A-sludge), (ii) sludge from the filtration/clarification of potable water (W-sludge), (iii) sludge
generated in marble sawing processes (M-sludge), and (iv) foundry sand (F-sand).
Two different formulations were prepared and bodies were shaped by extrusion, after its detailed
optimisation. Screw extruded rods were then fired at several temperatures and characterised in
terms of relevant functional properties (shrinkage, density and mechanical strength). Their electrical
insulating properties were assessed by impedance spectroscopy.
The design of interesting technological properties, such as high electrical and mechanical resistance,
refractoriness, etc, was found to be easily achievable by controlling the initial batch formulation
and/or the sintering schedule.
Abstract: The slag from steel plants or incinerators was tried to be recycled and be reused as foam
materials through plasma arc melting. The study was intended to investigate the making of foam slag
with laboratory plasma melting facilities. The investigated materials consisted of different mixtures
of Al2O3、SiO2 、FetO、CaO and Na2O, with the fluxes that were necessary to examine the
capability of pore-formation in the solidified ingots. It has been found that the foam slag could be
obtained with the proper compositions and conditions of arc heating. The dimensions and
distributions of pores were studied and correlated with the temperatures and compositions of slag.
The results showed that the sizes of pores inside the solidified ingots were in the range of 1~5 mm,
and the thickness of slag was around 20 mm. As to the distributions of the pores in the ingots of slag,
further improvement would be needed in the future.
Abstract: The preparation of ceramic pigments using industrial waste, a galvanizing sludge from
the Cr/Ni plating process, as primary source is here reported. The ceramic pigments were prepared
using the common solid state reaction process, investigating the optimal formulation, milling and
firing conditions. The main focus will be given on the synthesis of chrome-tin red malayaite
Ca(Cr,Sn)SiO5 pigment that was fully characterised and then tested in a standard ceramic glaze.
Typical working conditions and colour development will be also reported.
Abstract: Many kinds of industrial waste were examined as potential constituents of ceramic bricks
or tiles. The basic physical properties of these materials were measured, such as sintering
temperature, water absorption, porosity, density, color, chemical stability and bending strength.
Several kinds of sintered ceramics containing large amounts of waste materials were obtained by
adjusting the amount of the waste materials added to the ceramics. These were fired at temperatures
lower than 1000°C. A lowering of firing temperature results in a reduction of discharge of CO2 on
the production process. Ceramic brick with high water retention is expected to mitigate the heatisland
phenomenon by the latent heat of evaporation. Porous ceramics were prepared using
industrial waste, burned ash and recycled roofing tile as raw materials. The permeability, water
retentivity, water absorption, and other properties of the porous recycled ceramics were investigated.
The pF value of the ceramics was measured as an indicator of water retentivity. An appropriate
method of characterizing water retentive ceramic materials was also discussed based on results of
fundamental examination of the ceramics under practical conditions.
Abstract: “Bauxite Residue” (BR) is the main waste of alumina-producing Bayer process. With the
aim to use BR in the heavy clay industry, the plasticity of clay mixtures with BR was studied by the
“High Pressure Annular Shear Cell” (HPASC) technique. The information obtained is cohesion and
pressure dependence values that enable the determination of optimal conditions for extrusion. The
results for 30wt% BR addition, substituting the clay mixture, demonstrate that the maximum
cohesion is increased. Nevertheless, the water demand is increased for achieving the appropriate
cohesion and pressure dependence levels for extrusion, a factor that imposes increased demand for
drying. By shifting the particle size distribution towards a higher mean particle size, redesigning the
clay mixture or by polymer addition, the rheological behaviour of the paste can be adjusted.
Abstract: Carbon-containing refractory bricks are used extensively in the
steel industry worldwide. Since the first generation became commercially
available in the 1970’s, their processing, microstructures and properties have
been improved dramatically, and the service lives of industrial furnaces have
thus been extended substantially. In addition to the work on carboncontaining
refractory bricks, much effort has been, and is being, made
worldwide towards the development of carbon-containing refractory
castables. In this paper, the latest R & D towards new generation carboncontaining
refractory bricks as well as carbon-containing refractory castables
have been highlighted. In the first part, current techniques used to improve
mechanical properties of carbon-containing refractory bricks are
summarised. A new concept using a catalytic-growth technique to create insitu
oxide nanofibres and/or carbon nanotubes in carbon-containing
refractory bricks is introduced. The second part addresses some important
technical issues of low carbon carbon-containing refractory bricks. Besides
the concern about thermal shock resistance, other new problems arising
from the use of nanosized carbon, such as the accelerated MgO-C reaction
and carbon oxidation, are discussed. In the final part of the paper, technical
difficulties hindering the development of carbon-containing castables as
well as measures to overcome them are discussed. A novel molten salt
synthesis technique developed recently at Sheffield to prepare high quality
carbide coatings on graphite is introduced.