scholarly journals Structure of road soil cement compositions modified by complex additive based on organosilicon compounds and electrolytes

2019 ◽  
Vol 140 ◽  
pp. 02016
Author(s):  
Lenar Mavliev ◽  
Evgenii Vdovin
Keyword(s):  
Thermal Analysis ◽  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
Cement Clinker ◽  
Uniform Structure ◽  
Free Calcium ◽  
Soil Minerals ◽  
Cement Sample ◽  
Complex Additive ◽  
Soil Cement

The complex introduction of organosilicon compound (octyltriethoxysilane) and electrolyte (sodium hydroxide) maximizes the frost resistance and strength of soil cement. However, the effect of complex additive based on octyltriethoxysilane and sodium hydroxide on the soil cement structure has not been sufficiently studied. Therefore, the aim of this work was to study the phase composition of hydrated newgrowths and soil minerals in soil cement with optimal content of complex additives. The study was conducted by methods of complex thermal analysis, X-ray powder diffraction and electron microscopy. On the XRD pattern of the sample with and without complex additive, we marked identical peaks of soil minerals, unhydrated cement clinker minerals and hydrated newgrowths. In the result of differential thermal analysis, we determined that soil cement with complex additive is characterized by the smaller amount of free calcium hydroxide formed, as well as saturation of the soil complex with sodium ions. In the soil cement sample with complex additive, we observe a smaller amount of coagulated soil aggregates in comparison with the sample without an additive. Complex additive contributes to the formation of a more dense and uniform structure of soil cement, reduces the amount of adsorption water associated with clay minerals, reduces the formation of free calcium hydroxide, which increases the physicomechanical properties of the resulting material.

scholarly journals Recovery of Zinc from Treatment of Spent Acid Solutions from the Pickling Stage of Galvanizing Plants

2021 ◽  
Vol 13 (1) ◽  
pp. 407
Author(s):  
Svetlana B. Zueva ◽  
Francesco Ferella ◽  
Valentina Innocenzi ◽  
Ida De Michelis ◽  
Valentina Corradini ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
State Of The Art ◽  
Zinc Content ◽  
Economic Viability ◽  
Acid Solutions ◽  
Physical Chemical ◽  
Galvanic Sludge ◽  
Valuable Metals

Typical methods for the treatment of waste pickling solutions include precipitation by alkaline reagents, most commonly calcium hydroxide. As a result, large volumes of galvanic sludge form, containing iron, calcium, sulphates, and a relatively small quantity of zinc (<20%), making Zn recovery not profitable. In summary, state-of-the-art Zn galvanization processes entail the loss of valuable metals and the irrational and expensive handling of spent pickling solutions (SPSs). The resulting conclusion is that there is room for a significant improvement in the way SPSs are treated, with the double goal of enhancing Zn galvanization methods’ economic viability and achieving a lesser impact on the environment’s processes. The experimental results show that it is possible to use SPS as a coagulant to treat the process wastewaters, kept separated, and added with sodium hydroxide. The results in obtaining precipitates with Zn contents higher than 40%, increasing the added advantage of making Zn recovery profitable. The results show the possibility of using SPS as a coagulant in the process of physical-chemical wastewater treatment and sodium hydroxide to obtain a precipitate with a zinc content of more than 40%.

Effect of Sodium Hydroxide, Calcium Hydroxide, and Potassium Hydroxide on Debranning of Corn

1997 ◽  
Vol 74 (3) ◽  
pp. 254-257 ◽  
Author(s):  
S. K. Singh ◽  
N. Singh ◽  
L. Du ◽  
S. R. Eckhoff
Keyword(s):  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
Potassium Hydroxide

Comparison of sodium hydroxide and calcium hydroxide pretreatments of giant reed for enhanced enzymatic digestibility and methane production

2017 ◽  
Vol 244 ◽  
pp. 1150-1157 ◽  
Author(s):  
Danping Jiang ◽  
Xumeng Ge ◽  
Quanguo Zhang ◽  
Xuehua Zhou ◽  
Zhou Chen ◽  
...  
Keyword(s):  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
Methane Production ◽  
Giant Reed ◽  
Enzymatic Digestibility

Methyl Trichlorosilane Prepared Methyl Sodium Silicate

2012 ◽  
Vol 184-185 ◽  
pp. 1064-1067
Author(s):  
Guang Xia Zhang ◽  
Qiao Yun Zhang ◽  
Ze Min Chen
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Water Solubility ◽  
Experimental Results ◽  
White Powder ◽  
Molten State

This paper studied how to prepare Methyl Sodium Silicate from Methyl Trichlorosilane. Methyl trichlorosilane hydrolyzed on the interface of cyclohexane and water, then hydrolysate and sodium hydroxide prepared methyl sodium silicate at molten state. Manufactrue was characterised by XRD, IR, and differential thermal analysis. The experimental results indicate that the best hydrolyze condition was the proportion of methyl trichlorosilane and water was 10~12:100 , at 5°C, lasting for 45min; the best condition of prepared methyl sodium silicate was the proportion of sodium hydroxide and hydrolysate was 2.1~2.3:1, at 300 ~450°C, lasting for 50min. The manufacture was white powder, water-solubility and well stabilization bellow 450°C.

The Role of Sodium Hydroxide in the System C3A-CaSO4-H2O at 30°C

1986 ◽  
Vol 85 ◽  
Author(s):  
Hanaa Youssef Ghorab ◽  
Safaa Hussein Abou El Fetouh
Keyword(s):  
Solid Solution ◽  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
Hydration Product ◽  
Ion Concentration ◽  
Molar Ratio ◽  
Alkaline Solutions ◽  
Hydration Reaction ◽  
X Ray Diffraction

ABSTRACTThe hydration reaction of C3A with gypsum (molar ratio = 1:1.5) has been studied in water and in sodium hydroxide solutions at 30°C. The hydration product were analyzed microscopically and by means of X-ray diffraction. The concentration of sulfate and aluminum in solution was determined spectrophotometrically. In the absence of alkali, the amount of ettringite formed passes through a maximum and is accompanied by almost complete consumption of sulphate ion in solution. Alkali depresses the formation of ettringite and accelerates that of calcium hydroxide. The monosulfate hydrate appears immediately in alkaline solutions and water then reappears after a day as a solid solution with the tetracalcium aluminate hydrate. The formation of the monophase solid solution is accompanied by the consumption of C3A, ettringite, and calcium hydroxide and by an increase in the amount of the dissolved aluminum. The presence of alkali markedly increases the initial sulfate ion concentration from solution.

RECOVERY OF LACTOSE FROM AQUEOUS SOLUTIONS: PRECIPITATION WITH CALCIUM HYDROXIDE AND SODIUM HYDROXIDE

1980 ◽  
Vol 45 (2) ◽  
pp. 362-366 ◽  
Author(s):  
DOUGLAS B. MC COMMINS ◽  
RICHARD A. BERN HARD ◽  
T.A. NICKERSON
Keyword(s):  
Aqueous Solutions ◽  
Sodium Hydroxide ◽  
Calcium Hydroxide

The Phase Transformation of Recycling Concrete in Recalcination

2013 ◽  
Vol 743-744 ◽  
pp. 175-179 ◽  
Author(s):  
Zhi Gang Zhang ◽  
Zong Hui Zhou ◽  
De Cheng Zhang ◽  
Xin Cheng
Keyword(s):  
Phase Transformation ◽  
Calcium Hydroxide ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Eutectic Temperature ◽  
Experimental Results ◽  
Industrial Wastes ◽  
Cement Clinker ◽  
Temperature Range ◽  
Natural Aggregates

In this paper, the artificial aggregates were prepared by limestone and industrial wastes in accordance with the ratio of cement raw meal, to obtain the recycling concrete replacing natural aggregates. Cement clinker could be regenerated by these recycling concrete and the aim of recycling could be realized. After these concrete was cured for 90 days, then was crushed and grinded, the phase transformation of recycling concrete in recalcination would been studied by XRD and so on. The experimental results showed that the composition of the recycling concrete met the demand of clinker modulus and C2S, C3S, C4AF, C3A were well crystallized at 1400 °C. So these recycling concrete could be directly calcined. The calcium hydroxide dehydrated around the temperature of 500°C. The calcium silicate hydrate was dehydrated gradually between the temperature of 400°C and 1000°C. At the same time, C2S crystallized during the temperature range. C4AF and C3A stared to crystallize around the temperature of 1000°C. Due to the composition of these concrete was complex, the lowest eutectic temperature dropped. C3S started to crystallize around the temperature of 1250°C and the best crystallization was achieved at the temperature of 1400°C.

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