scholarly journals Sodium Hydroxide and Calcium Hydroxide Hybrid Oxygen Bleaching with System

2018 ◽  
Vol 301 ◽  
pp. 012136
Author(s):  
K Doelle ◽  
B Bajrami
Keyword(s):  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
Oxygen Bleaching

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

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.

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

scholarly journals Bleaching Flax Roving With Poly(Acrylic Acid) Magnesium Salt As Oxygen Bleaching Stabilizer For Hydrogen Peroxide

2021 ◽  
Author(s):  
Jie Liu ◽  
Wenqi Jiang ◽  
Ling Sun ◽  
Chun Lv
Keyword(s):  
Hydrogen Peroxide ◽  
Acrylic Acid ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Magnesium Salt ◽  
Capillary Effect ◽  
Sodium Hydroxide Concentration ◽  
Silicon Oxygen ◽  
Oxygen Bleaching ◽  
Poly Acrylic Acid

Abstract Alkali-oxygen one-bath scouring and bleaching process of the flax roving was studied by using a new type of synthesized non-silicon oxygen bleaching stabilizer Poly(acrylic acid) magnesium instead of sodium silicate. Based on the analysis of the effects of single factors such as sodium hydroxide concentration, hydrogen peroxide concentration, temperature, time and the amount of the synthesized non-silicon oxygen bleaching stabilizer poly(acrylic acid) magnesium salt on the performance of the bleached flax roving, including the whiteness, the breaking tenacity, the capillary effect and the weight loss ratio. The optimal process for the application of the stabilizer was determined by orthogonal test, namely, hydrogen peroxide concentration 8.5 g/L, sodium hydroxide concentration 5 g/L, sodium bisulfite 3 g/L, sodium carbonate 3 g/L, the synthesized non-silicon oxygen bleaching stabilizer poly(acrylic acid) magnesium 5.5 g/L, scoured and bleached at 90 ℃ for 60 min, and the bath ratio was 25:1. Compared with the traditional oxygen bleaching stabilizer sodium silicate, it not only has good ability to inhibit the rapid decomposition of hydrogen peroxide, but also has the advantages of higher whiteness, higher capillary effect, good feel and breaking tenacity, and can effectively solve the "silicon scale" problem and improve the quality of flax products.

scholarly journals Interaction of Magnesia with Limestone-Metakaolin-Calcium Hydroxide Ternary Alkali-Activated Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
A. Cwirzen ◽  
L. Metsäpelto ◽  
K. Habermehl-Cwirzen
Keyword(s):  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
Sodium Silicate ◽  
Ternary Systems ◽  
Sodium Sulphate ◽  
Crystalline Phases ◽  
Amorphous Phases ◽  
Porous Microstructure ◽  
Alkali Activated

The effect of magnesia on ternary systems composed of limestone, metakaolin and calcium hydroxide, alkali activated with sodium silicate, sodium hydroxide, and sodium sulphate was studied by determination of the compressive strength, X-ray powder diffraction (XRD), thermogravimetry (TG), and scanning electron microscope (SEM). Pastes activated with sodium silicate and sodium sulphate showed strength regression caused by a formation of an unstable prone to cracking geopolymer gel. The presence of magnesia in sodium hydroxide-activated system hindered this trend by promoting a formation of more stable crystalline phases intermixed with brucide. In general, magnesia densified the binder matrix by promoting a formation of amorphous phases while sodium hydroxide produced the most porous microstructure containing high amount of crystalline phases.

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