Papers by Keyword: Diatomaceous Earth

Abstract: This paper explores the possibilities of utilization of waste diatomite in foam glass production. Chemical and mineralogical composition, granulometry and high temperature behaviour of waste diatomite were characterized. Different possibilities of waste diatomite utilization in foam glass production were explored mainly via means of thermal analysis and hot stage microscopy. The effects of diatomite addition to waste glass were evaluated. Possibility of using NaOH as a foaming agent for foam glass production from waste diatomite and the effects of NaOH amount and reaction time on waste diatomite were investigated. Partial conversion of diatomite and clay to hydrates due to the reaction with NaOH lead to the decrease of the melting temperature and foaming of the melt was observed via hot stage microscopy. 30 wt. % NaOH addition allowed foaming of waste diatomite in the temperature ranges typical for foam glass production. Increased reaction time led to the intensification of the foaming process.

Abstract: In this research, calcined diatomaceous earth from Aceh Besar, Indonesia was used as cement replacement in producing high strength concrete. Four concrete mixtures in which the percentage of cement replacement of 0%, 5%, 10% and 15% by weight were studied. Four cylinder-specimens with 100 mm diameter and 200 mm high were prepared for each mixture. The compression load was applied on the specimens at the age of 28 days until the specimens failed. The mixture without calcined diatomaceous earth was more workable than that with diatomaceous earth. The compressive strength of concrete with diatomaceous earth in this study was almost the same for all mixture. However, those compressive strength was lower than the compressive strength of concrete without calcined diatomaceous earth for about 14.6%. Modulus of elasticity of high strength concrete decreased with increasing of cement replacement percentage.

Abstract: In residential and industrial buildings, a special air environment is formed, which contains gas shaped toxic chemical compounds. A significant part of such substances comes from finishing polymer containing materials. Virtually all polymeric materials release certain toxic chemical compounds into the air. The methods and methods of air cleaning are different. One of the ways to solve the problem associated with providing the required standards for the quality of indoor air is the development and use of new efficient building materials using aggregates that have a high sorption capacity. The paper presents the results of a study of the effect of low temperature non-equilibrium plasma on the sorption characteristics of aggregates based on diatomite earth. Studies have been conducted on samples of natural diatomite and quartz sand. When activated by low temperature nonequilibrium plasma, the structure changes, which leads to an increase in the sorption characteristics of the samples under study.

Abstract: This study used an optimized mixture of red mud (RM), rice husk ash (RHA), diatomaceous earth (DE), and water glass solution (WGS) with silica modulus of 2.5 to produce geopolymer-based material. The geopolymer product was tested engineering properties which are in good agreement of ASTM requirements for building materials. For microstructure, the geopolymer samples were characterized by using Fourier-transform infrared spectroscopy (FTIR) and focused on evaluation on formation of aluminosilicate network in the ternary-blended geopolymer. The results showed that tetra-silicates or acid silicic (Si (OH)₄ or H₄SiO₄) dissolved and reacted with the iron oxide (Fe₂O₃) in RM and DE to form the oligomer precursors of sialate-O-Si-O-Al-O-, sialate-siloxo-O-Si-O-Al-O-Si-O-, sialate-disiloxo-O-Si-O-Al-O-Si-O-Si-O-, tetra-silicate [SiO₄]^4-, and tetra-aluminate [AlO₄]^4-. The formation of sodium alumino-silicate iron hydroxide polymeric network were easily detected by vibrational modes of –T–O–T– and –T–O–Na units (T refers to tetrahedral such as that of Si or Al) and of –OH and H–O–H. As well as, there were appearances of the membered ring or chain structural units of geopolymers.

Abstract: This paper deals with determination of basic physical, mechanical, thermal and water transport properties of lime–based plasters whose composition was modified by the addition of diatomaceous earth. To eliminate possible deterioration of original lime plaster by natural weathering, the hydrophobic admixtures on the stearate and oleate basis were added into the plaster mixtures and boiled linseed oil as a painting was applied. All studied material parameters were tested after 28 days of wet curing and after exposition to accelerated carbonation. The results of examined properties of developed plasters gave promising outcomes for the use of hydrophobised materials in renewal of historical buildings. Based on the obtained data, plaster made of lime hydrate, diatomite, and combination of water repellent agents can be recommended for renovation purposes.

Abstract: Paper is aimed at study of preparation possibilities of cementitious binders with waste diatomaceous earth. In the first step, the influence of ground diatomaceous earth on properties of cement mixture was studied. In the next step, diatomaceous earth was calcinated and, lastly, the influence of replacing FGD-gypsum with anhydrite II as a setting controller in the mixture containing calcined diatomaceous earth was monitored. Technological properties of the prepared mixtures were measured and compared with cement standard. For studying the influence of phase composition and microstructure of cements hardened by both untreated and calcinated diatomaceous earth, hardened cements were tested by DTA and their porosities were measured. The results show that it is possible to prepare binder containing calcinated diatomaceous earth which has slightly lower early strengths but higher long-term strengths and lower hydration heat development.

Abstract: In this study, three kinds of natural clay minerals (kaolin clay, montmorillonite and diatomaceous earth) were used to treat the raw water containing humic acid (HA) by adsorption/sedimentation. The results indicated that natural kaolin clay had no obvious effect on removing HA in water. Using chitosan to modify montmorillonite and diatomaceous earth, the removal effect of the modified diatomaceous earth for HA was better than modified montmorillonite, and the optimal ratio between chitosan and diatomaceous earth was 1:30. Compared with natural diatomaceous earth, the modified clay had better adsorption property for HA at the same dosage. Using modified diatomaceous earth, the maximal removing rates for TOC and turbidity could respectively reach 85.9% and 64.6% with 60 mg/L dosage and 50 min.

Abstract: Taking the raw water of Yangtze Chenhang Reservoir as the research object, the characterization of diatomaceous earth, and the removal efficiency of COD_Mn, turbidity by precoat filtration process were investigated by pilot experiment in this paper. The results showed that diatomaceous earth patterns having porous structure and the pure silica peak at 2θ angles 21.980, 36.080, 31.460 and 28.430 in XRD analysis. Precoat filtration has a good stability to remove solid suspended particle, effluent turbidity was remained about 0.05NTU. Precoat filtration had no effect on removing COD_Mn. The pressure of 50KPa could be defined as a critical point in this experiment. Beyond the critical point, the devices should be stop and backwash, to resume operation pressure. Overall, precoat filtration can be defined as a filtration technique for relatively low turbidity raw waters.

Abstract: A well-defined porous ceramic having effective pore size less than 1 µm was fabricated by slip casting technique which provides a low-cost and single-stage filtration process. This single-stage filtration process removed suspended solids and pathogenic organism. In this study, diatomaceous earth was used as pore forming agent in clay based ceramic body. Varied amount of diatomaceous earth was used with fixed proportion of china clay, ball clay and lime stone. X-ray fluorescence spectroscopy (XRF) was used to determine the composition of raw materials and final sintered filter body. In terms of porosity and flow rate, 25% diatomaceous earth shows better filtration property. It was found that total porosity increased with decreasing milling time. As the firing temperature increased, porosity decreased rapidly after 1100 °C. However, the change of porosity in firing range of 1000 °C–1100 °C was found very small. Mercury intrusion porosimetry was used to measure the pore size and its distribution. An effective intra-particle pores in a range of 0.2-0.5 μm was identified. Inter- and intra-particle pores were observed using scanning electron microscope (SEM). Microbial removalefficiency of 99.99% was measured, while water flow rate was found in a range of 200-700 ml/hour.

Abstract: This test is mainly diatomaceous earth mineral admixture to study the content, calcination temperature, calcination time, grinding time on the properties of concrete, and through the use of SEM, XRD and other means of micro-theory analysis. The results showed that, after calcination or ball mill grinding, diatomaceous concrete admixture used to increase strength, improve durability of concrete. When the diatomite calcination temperature to 650 ,content is 2%, the volcanic activity to achieve the best value, the calcination time increased strength increases, strength increases flattened when the rate of more than 2h.