Mechanisms of grinding modification by chemical additives: organic reagents

1984 ◽  
Vol 38 (3) ◽  
pp. 267-273 ◽  
Author(s):  
H. El-Shall ◽  
P. Somasundaran
Keyword(s):  
Chemical Additives ◽  
Organic Reagents

scholarly journals Current Aspects of Prevention of Coal Freezing by Means of Inorganic and Organic Reagents

2021 ◽  
Vol 100 ◽  
pp. 06003
Author(s):  
Ekaterina Shmeltser ◽  
Maryna Kormer ◽  
Vitalij Lyalyuk
Keyword(s):  
Alkaline Earth ◽  
Physicochemical Characteristics ◽  
Cold Season ◽  
Chemical Additives ◽  
Organic Reagents ◽  
Alkaline Metals ◽  
Structure Of Molecules ◽  
Coke Plants ◽  
Composition And Structure ◽  
Effective Use

In the cold season, irregular coal supplies to coke plants are aggravated by the need to heat the coal cars. Thawing of rail cars in garages (enclosures) is the least efficient and most expensive approach. Treatment of the coal concentrates with chemical additives reliably prevents freezing in winter during transit from suppliers to consumers. With a view to finding new reagents for preventing the freezing of coal in winter, the lime, the acetates and chlorides of alkaline-earth and alkaline metals are studied. Attention focuses on their physicochemical characteristics, methods of preparation and of introduction in coal concentrate, and their influence on freezing. The results of studies have shown that the use of organosilicon is more effective use of acetates and chlorides of metals. The high activity of organosilicon substances is explained by their elemental composition and structure of molecules.

Effects of particle sizes, wood to cement ratio and chemical additives on the properties of sesendok (Endospermum Diadenum) cement-bonded particleboard

2010 ◽  
Vol 7 (2) ◽  
pp. 57
Author(s):  
Jamaludin Kasim ◽  
Shaikh Abdul Karim Yamani ◽  
Ahmad Firdaus Mat Hedzir ◽  
Ahmad Syafiq Badrul Hisham ◽  
Mohd Arif Fikri Mohamad Adnan
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Cement Content ◽  
Particle Sizes ◽  
Thickness Swelling ◽  
Chemical Additives ◽  
Board Density ◽  
Cement Ratio ◽  
Aluminium Silicate ◽  
Cement Board

An experimental investigation was performed to evaluate the properties of cement-bonded particleboard made from Sesendok wood. The target board density was set at a standard 1200 kg m". The effect offarticle size, wood to cement ratio and the addition ofsodium silicate and aluminium silicate on the wood cement board properties has been evaluated. A change ofparticle size from 1.0 mm to 2.0 mm has a significant effect on the mechanical properties, however the physical properties deteriorate. Increasing the wood to cement ratio from 1:2.25 to 1:3 decreases the modulus ofrupture (MOR) by 11% and the addition ofsodium silicate improves valuesfurther by about 28% compared to the addition ofaluminum silicate. The modulus ofelasticity (MOE) in general increases with increasing cement content, but is not significantly affected by the addition ofsodium silicate or aluminium silicate, although the addition of their mixture (sodium silicate andaluminium silicate) consistentlyyields greater MOE values. Water absorption and thickness swelling is significantly affected by the inclusion ofadditives and better values are attained using higher wood to cement ratios.

Chemical Additives for Maximizing Fuel Reactivity

2000 ◽  
Author(s):  
Vladimir M. Zamansky ◽  
Vitali V. Lissianski ◽  
Mark S. Sheldon ◽  
Eric L. Petersen
Keyword(s):  
Chemical Additives

Removal of Residual Nutrients and Chemical Additives From Secondary Sewage by Reverse osmosis

1975 ◽  
Vol 10 (1) ◽  
pp. 101-109
Author(s):  
H. Kirk Johnston ◽  
H.S. Lim
Keyword(s):  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Pilot Plant ◽  
Waste Treatment ◽  
Iron Chloride ◽  
Treatment Technique ◽  
Chemical Additives ◽  
Cellulose Acetate Membranes ◽  
Municipal Wastewaters ◽  
Nutrient Solutions

Abstract The suitability of reverse osmosis as a renovation technique for the treatment of municipal wastewaters has been assessed. Cellulose acetate membranes capable of 70% and 90% NaCl rejections were employed in both laboratory and pilot plant studies to evaluate the efficiency of this technique in removing the residual precipitant chemicals generally employed in phosphorus removal programs (iron chloride, alum, and lime) and the nutrients (phosphates, nitrates and ammonia) characteristic of municipal wastewaters. Secondary sewage and raw sewage as well as prepared nutrient solutions were employed in the course of this program. Both laboratory and pilot plant studies indicated consistently outstanding removal efficiencies for the species examined, almost independent of the nature of the waste solutions being treated. Permeation of the purified effluent was subject to significant reductions due to membrane fouling. This characteristic was most pronounced for the more permeable (less selective) membranes. Routine chemical and physical cleanings enable satisfactory flux levels to be maintained, thereby suggesting that reverse osmosis may become a viable municipal waste treatment technique.

Simultaneous Sorption of Chelates of Elements with Organic Reagents on Amberlite XAD-2 as a Preconcentration Step for the Emission Spectrometric Determination of the Elements

1993 ◽  
Vol 58 (8) ◽  
pp. 1821-1831 ◽  
Author(s):  
Jaroslav Jambor ◽  
Tomáš Javorek
Keyword(s):  
Nitrous Oxide ◽  
Argon Plasma ◽  
Electric Arc ◽  
Emission Spectrometry ◽  
Organic Reagents ◽  
Inductively Coupled ◽  
Simultaneous Sorption

The macrophorous hydrophobic sorbent Amberlite XAD-2 proved to be well suited to the preconcentration of minority amounts of Al, Au, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sn, Ti and V in the form of their chelates with organic reagents. From among 14 reagents tested, 8-hydroxyquinoline and diethyldithiocarbamate appeared most suitable for the quantitative sorption up to level of 1 μg l-1 of analyte. Emission spectrometry served as the analytical finish; the nitrous oxide-acetylene flame, electric arc and inductively coupled argon plasma were chosen according to the nature of the element. The procedure is convenient for the determination of the minority analytes in waters

scholarly journals Rutting and moisture-induced damage potential of foamed warm mix asphalt (WMA) containing RAP

2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Mohammad Ashiqur Rahman ◽  
Rouzbeh Ghabchi ◽  
Musharraf Zaman ◽  
Syed Ashik Ali
Keyword(s):  
Asphalt Pavement ◽  
Warm Mix Asphalt ◽  
Environmental Benefits ◽  
Reclaimed Asphalt Pavement ◽  
Chemical Additives ◽  
Flow Number ◽  
Damage Potential ◽  
Asphalt Mixes ◽  
Reclaimed Asphalt ◽  
Wheel Tracking

AbstractDespite significant economic and environmental benefits, performance of warm mix asphalt (WMA) containing reclaimed asphalt pavement (RAP) remains a matter of concern. Among the current WMA technologies, the plant foaming technique (called “foamed WMA” in this study) has gained the most attention, since it eliminates the need for chemical additives. In the present study, the laboratory performance, namely rutting and moisture-induced damage potential of foamed WMA containing RAP were evaluated and compared with those of similar hot mix asphalt (HMA) containing identical amount of RAP. Dynamic modulus, Hamburg wheel tracking (HWT) and flow number tests were performed to assess the rutting resistance of the mixes. Also, stripping inflection point from HWT tests and tensile strength ratio after AASHTO T 283 and moisture induced sensitivity test (MIST) conditioning were used to evaluate the moisture-induced damage of asphalt mixes. It was found that MIST conditioning effectively simulates the moisture-induced damage and can capture the propensity of asphalt mixes to moisture damage more distinctly compared to AASHTO T 283 method due to application of cyclic loadings. The foamed WMA was found to exhibit higher rutting and moisture-induced damage potential due to lower mixing and compaction temperatures compared to HMA. However, the increase in RAP content was found to reduce rutting and moisture-induced damage potential for WMA. Therefore, the lower stiffness of foamed WMA may be compensated with the addition of stiffer binder from RAP.

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