Chrome slag, the new favorite of the most popular

Chrome slag, the "new favorite" of beer bottle colorant, according to relevant information, chemical plants that produce chromate will produce 4 ~ 5T waste residue per production of LT chromate, and the annual waste residue in the country reaches 273000 t. Taking a chemical plant in Liaoning as an example, 130000 tons of waste residue were not treated in the past

such a large amount of waste will not only seriously pollute the environment, but also cause chrome sores, nasal perforation and other difficult to treat diseases if exposed for a long time. How to turn waste into treasure and turn harm into benefit is an important topic in today's research

hardness is a performance index to measure the degree of softness and hardness of materials. As a traditional packaging container, glass cans have a long history of canned beverages. Because it has the advantages of good chemical stability, no pollution of contents, transparency, cleanness, beauty, good sealing performance, durability, low price, it still has strong vitality. In recent years, the production of glass bottles and cans in China has developed rapidly, and the output is increasing day by day. According to the information of the glass container committee of China Packaging Technology Association, there are more than 150 glass bottle and can factories nationwide, with an output of 500t, of which emerald green glass products account for one third

most colorants of original green glass are metal compounds containing chromium. Generally, sodium dichromate, a chemical raw material, is used as colorant, and the price per ton is 1800 yuan. Chromium slag, a waste from the production of sodium dichromate and potassium dichromate in chemical plants, is processed and crushed into powder as a colorant for glass, with a price of about 200 yuan per ton. If the annual output of 66000 tons of glass products is used to replace sodium dichromate with chromium slag, the annual consumption of chromium slag is 1267t, while the annual consumption of sodium dichromate is 173t, and the price of sodium dichromate is l73 × 1800=311400 yuan; The price of chrome slag is 1267 × 200 = 253400 yuan. The difference is 580, but we'd better take the standard sample of 00 yuan

choosing chromium slag as colorant has the following advantages:

First: it can turn waste into treasure, turn harm into benefit, and reduce environmental pollution

II: chromium slag has low melting point and is easy to melt, which can reduce the melting temperature, save energy, reduce costs and improve economic benefits

III: chromium slag powder contains a small amount of chromium, and the coloring ability of chromium ion is very strong. The dosage of chromium slag powder in the batch is 3 ~ 4 times larger than that of sodium chromate. Because of its uniform distribution, it is not easy to make glass products appear black spots and pimples

in terms of composition, Cr2O3 accounts for 54.37% and Na2O accounts for 20% of sodium dichromate

in chromium slag, SiO2 accounts for 8.26%, Al2O3 accounts for 7.86%; Fe2O3 accounts for 13.38%, Cao accounts for 30.68%; MgO accounts for 21.76%, Cr2O3 accounts for 4.61%

the formula of beer bottle is (%): SiO2 Al2O3 Fe2O3 Cao MgO Na2O Bao SO3 Cr2O3 67.72 6.04 0.59 7.58 2.32 14.44 0.83 0.36 0.10

in the formula, in order to reduce the expansion coefficient of glass and improve its chemical stability and mechanical strength, the SiO2 content is 67.72%, while the composition of beer bottle is mainly sodium calcium silicon. The introduction of a certain amount of Al2O3 into soda lime silica glass with soda lime silica as the main body can reduce the crystallization property of the glass and improve the chemical stability of the glass. The introduction of MgO can reduce the crystallization tendency, while the introduction of Na2O can reduce the viscosity of the glass and make the glass easy to melt. It is a good flux for liquid glass

as for the determination of the amount of colorant Cr2O3, it is not allowed to make the color too dark or too light. If it is too deep, the heat permeability is too poor, and if it is too light, the heat permeability is too strong. Therefore, the product is emerald green, and the amount that meets the requirements is Cr2O3 with mass fraction =0.1%. It can be seen that chromium slag can completely replace sodium dichromate as colorant

in the process of using chromium slag in a glass factory in Qingdao, according to the provisions of the national standard gb451l-91 for beer bottles, all of them are qualified, and the following experience and experience have been explored in practice:

1) there is no technical problem in using waste chromium slag powder as a glass colorant, and it can be widely promoted and applied. Taking the annual output of 66000 tons of beer as an example, the annual treatment of 1500t waste residue can save 184000 yuan. At present, the output of emerald green beer bottles in China is about 1.6 million tons, but after entering the 21st century, 3600t waste residue can be treated in the whole year after the adoption of this technology, saving 4.432 million yuan

2) the particle size of chromium slag powder is required to pass the 80 mesh sieve. If it is too coarse, it will bring difficulties to melting 281 insulating electrical bushings and accessories for construction, and the products appear black spots

3) in the whole production process of purchased waste, from raw materials entering the plant to all production links, we should strictly control and strictly implement the process procedures, especially to ensure the management and measurement of chromium slag powder, which is a powerful guarantee to improve the product quality

4) for other raw materials, especially waste glass, clean and remove sundries after entering the plant, and the crushing specification is 30 × About 30mm, which can meet the feeding requirements and is easy to melt

5) for various reasons, a large amount of chromium slag waste has not been reused for industrial production on a larger scale. Accumulation and storage will not only pollute farmland and rivers, endanger people's health, but also be a heavy burden for chromium salt manufacturers across the country