Two batches of cement products in Shaanxi failed to pass the sampling inspection

Recently, Shaanxi Provincial Market Supervision and Administration has organized provincial supervision and spot checks on the quality of eight kinds of products, such as cement. The products of this spot check are cement, Portland cement clinker , flange, cold water meter, valve, stainless steel vacuum cup, stainless steel pipe for drinking water, wood-based panel and other eight products. A total of 269 batches of products produced by 193 enterprises were sampled and inspected, and 9 batches of unqualified products were found, including 1 batch of cement, 1 batch of Portland cement clinker, 2 batches of flanges and 5 batches of wood-based panels. Analysis of

spot check results:

(I) Cement

This time, 91 batches of products produced by 88 enterprises were sampled in the production fields of Xi'an, Baoji, Xianyang, Hanzhong, Ankang and other areas, and 1 batch of unqualified products was found, with an unqualified rate of 1.1%. Ten items, including sulfur trioxide, magnesium oxide, chloride ion, loss on ignition, setting time, stability, strength, radioactivity, water-soluble chromium and water retention rate, were tested. The unqualified items involved water-soluble chromium. According to the analysis of technical institutions, the main reason for the disqualification is the high chromium content in the raw materials and preparation process of cement.

(2) Portland cement clinker

This time, 38 batches of products produced by 31 enterprises in Baoji, Xianyang, Hanzhong, Ankang and other areas were sampled, and one batch of unqualified products was found, with an unqualified rate of 2.63%. Ten items, such as free calcium oxide, magnesium oxide, loss on ignition, insoluble matter, calcium oxide/silicon dioxide mass ratio, tricalcium silicate + dicalcium silicate, setting time, soundness, compressive strength and tricalcium aluminate, were tested. The unqualified items involve compressive strength. According to the analysis of technical institutions, the main reason for the disqualification is that the quality of raw materials used to prepare general cement clinker is unstable or the temperature in the kiln is unstable during the calcination of clinker, which leads to the failure of compressive strength to meet the standard requirements.