The chemical laboratory is responsible for carrying out a series of checks to raw materials (clinker, limestone and gypsum), the intermediate product (process) and the finished product (bulk bag) to ensure it meets quality standards set by Cementos Barrero to satisfy all its customers and in turn meet the standards for the manufacture of Portland cement.
- Control of raw materials: these components must be keept track of, as they have a decisive influence on the quality of the final product. Reception control is carried out as well as monitoring the quality of our suppliers. A summary of studies carried out on raw materials and their frequency are shown in the table below:
Humidity Fire Losses RX Free lime Sulfates Methylene blue Clinker (*) (*) (*) (*) —– —– Limestone 1/day 1/day 1/day —— —– 1/week Gypsum 1/day —— 1/day —— 1/week —–
(*) Every day.
- Process control::
Fineness RX Resistance Every two hours in production Every day Every day
- Control of the finished product: a summary of all the tests performed on finished products as is standard are shown in the following table:
Property Testing methods Frequency normal period Initial Resistance (2d) EN 196-1 2 trials/ week Normal Resistance (28d) EN 196-1 2 trials/ week First setting EN 196-3 2 trials/ week Final setting EN 196-3 2 trials/ week Volume stability EN 196-3 2 trials/ week Content on SO3 EN 196-2 2 trials/ week Content on chlorides EN 196-21 1 trial/ week Composition UNE 80216:1991 1 trial/ week Chrome UNE-EN 196-10 2 trials/ week
In the laboratory, there is a muffle furnace (reaches a temperature up to 1200° C) for calcining the samples and obtaining fire losses.
We have a RX fluorescence spectrometer that measures up to 11 elements and is calibrated for all raw materials and cement, thus you can know the composition of the sample more quickly than if we test via analytica.
Weekly it is verified by employers if the equipment has altered and also monthly analytical analysis of raw materials and cement are made to verify that the equipment is measuring correctly.
The fineness of the cements is determined in the laboratory by Permeability Blaine. We have two, one manual and other automatic. The fineness of cement is measured as specific surface, by observing the time it takes a fixed amount of air to pass through a compact layer of cement with specified dimensions and porosity.
In the control room we have a particle size analyzer, it lets us know the size distribution of the sample in question, in the range 0020-2000 microns.
We have also acquired a UV spectrophotometer for the determination of chromium (VI), which can cause allergic reactions in certain circumstances when human skin is in direct and prolonged contact with the cement, so the cement is analyzed daily to check that the levels of chromium are less than 2 ppm.