Nanjing Tech University

Nanjing University of Technology

Suhua Ma

Xiaodong Shen

Lin Chen

Weifeng Li

Xuerun Li

Weiqiang Zhou

Song Deng

Jin Yu

Yueyang Hu

It discloses cement grinding aids prepared with waste antifreeze which comprises the following components in parts by weight: 20-75 parts of pretreated waste antifreeze, 5-40 parts of alkanolamine, 1-5 parts of acid solution, 3-12 parts of saccharide and 15-50 parts of water. The pretreated waste antifreeze is prepared by adding an alkaline solution into waste antifreeze to regulate the pH value, adding a flocculant, and stirring and standing; separating upper-layer oil, and then filtering to remove flocculent precipitates, thus obtaining a clear mixed solution.

Cement grinding aids prepared with waste antifreeze

A chemical additive for calcium sulphoaluminate-modified Portland cement comprises the following substances: (a) at least one alkanolamine borate; (b) at least one organic alcohol; and (c) at least one saccharide or a derivative thereof; and the substances and water are sequentially mixed and stirred to obtain the chemical additive for calcium sulphoaluminate-modified Portland cement. The chemical additive for calcium sulphoaluminate-modified Portland cement provided by the invention has better effects of regulating the setting time of the calcium sulphoaluminate-modified Portland cement and improving the 3d/28d strength increase rate, and also has a grinding aid effect when being added during grinding.

Chemical additive for calcium sulphoaluminate-modified portland cement

The present invention relates to a process of controlling crystal form of Alite in Portland cement clinker, wherein the said Portland cement clinker is thermally treated in order to change the crystal form of Alite in Portland cement clinker, so as to improve performance of resulting Portland cement clinker. The said process of present invention is easy and feasible.

Process for controlling a crystal form of alite in portland cement clinker

A method for secondarily synthesizing calcium sulphoaluminate mineral in Portland cement clinker is provided. The method includes adding gypsum into raw Portland cement, calcination, then heating twice to re-form calcium sulphoaluminate mineral that has decomposed at high temperature in the clinker. This method can increase the content of calcium sulphoaluminate mineral in the clinker. As a result, the advantages of the calcium sulphoaluminate mineral in the clinker may be obtained, such as improvement of the early stage performance and long-term performance of the cement clinker and increase in the quantity of mixture in the cement.

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Nanjing, China

Suhua Ma