CN1061769A - Chromium slag Shi matter brick and preparation method thereof - Google Patents

Abstract

The present invention relates to a kind of chromium slag Shi matter brick and preparation method thereof.It is by the loess plate, and chromium slag and grog are formed.In sintering procedure, adopt the long technology of protecting of high temperature, not only thorough to the detoxifcation of chromium, and the yield rate height, indexs such as the physical strength of brick all are better than other chromium slag brick.The present invention is turned waste into wealth, and for material of construction has been opened up raw material sources, and can promote the production of chromium and chromic salts.

Description

Chromium slag Shi matter brick and preparation method thereof

The present invention relates to material of construction and preparation method thereof, a kind of inscription slag Shi matter brick and preparation method thereof of more specifically saying so.

The chromium slag is a main refuse of producing chromium metal and chromic salts, has toxicity because of containing sexavalent chrome, if untimely processing, could the serious environment pollution and the destruction eubiosis.The present method of handling the chromium slag has multiple, but the detoxifcation that has is not thorough, and what have is uneconomical, and the popularization that has is had any problem.Wherein useful chromium slag is made the method for building brick, as blue bricks [" China Environmental Science " 2(4), 55(1982)], [" metallurgical industry waste residue treatment process with utilize scientific and technological achievement compilation " (five) P.249 for common brick, 1985], chromium pulp water adobe [" metallurgical industry waste residue treatment process with utilize scientific and technological achievement compilation " (five) P.151,1985] or the like.But these bricks are because firing temperature is lower than 1000 ℃; The glassy phase content that generates is lower than 20%, and chromic transformation efficiency is low, so detoxifying effect and physical strength are all unstable, thereby has influenced applying of these methods.A kind of method of firing stoneware with the chromium slag is disclosed in " utilizing the chromium slag to fire the experimental study of stoneware product " [" Environmental Pollution and Control " 1989.1.Vol.11.NO.1.P6-12] literary composition, this product and method can be separated the toxicity in the dechromisation slag preferably, but therefore the processing condition of the unexposed industrial-scale production of this article can't be applied.

The object of the invention provides a kind of strong toxicity of separating, physical strength height, chromium slag Shi matter brick of stable performance and preparation method thereof.

For guarantee chromium slag in the Shi matter brick to separate toxicity good, higher physical strength and high rate of finished products are arranged, the present invention has adopted following prescription: the loess plate: the chromium slag: grog=55～65: 17～23: 23～17(weight percent).Simultaneously, in sintering procedure, adopted the technology of the long guarantor of high temperature, normal pressure reducing atmosphere.Firing temperature is 1150～1210 ℃.Temperature is low excessively to make chromium residue detoxifying incomplete, and temperature is too high, and the finished product rate is low.Shi matter brick is in sintering procedure, and temperature will be controlled different heat-up rates by different steps, to guarantee the quality of product.There is not sewage to occur in the whole process flow in order to make, the present invention adopts half-dried molded technology, promptly in raw material pulverizing, adds 6～10% moisture, make the powder that enters in the storage bin become moist half-dried material, thereby prevented the harm of dust and sewage environment and human body.The specification of Shi matter brick of the present invention is 238 * 238 * 52(mm), and chromium slag and other component granularity are the 30+5 order.Adopt the not board-like small cross-section tunnel furnace of horse can guarantee being heated evenly of brick, particularly little situation to firing range.

Fig. 1 is the flow diagram of manufacturing process of the present invention.

As seen from Figure 1, raw material loess plate, chromium slag, grog (referring to the building brick defective goods) are weighed by proportioning, then use crusher in crushing, further be crushed to 30 ± 5 orders with pulverizer again, and screening. Add 6～10% water when pulverizing, deposited ageing 2～3 days, then make adobe with forming machine, the adobe drying of making to water content is below 3%, can deliver in the kiln and burn till. For guaranteeing detoxifcation fully, yield rate is high, divides four-stage with sintering process, strictly controls temperature and the programming rate in each stage in sintering process. Phase I is the evaporation phase, from normal temperature to 300 ℃, wants slow at this stage programming rate, prevent that general control was at 16～24 hours because of the too fast base substrate spalling that makes that heats up; Second stage is oxidation Decomposition and transformation of crystal phase, temperature is 300 to 950 ℃, and during this period, blank structure water continues to get rid of, organic matter, inorganic matter carry out oxidation in the base substrate, carbonate, sulfide begin to decompose, and crystal formation begins to transform, in crystal transfer, about 14% expansion will occur in its volume, the too fast meeting that heats up makes the base substrate spalling, causes substandard products, and this stage generally needs 13～22 hours; Phase III is that vitreous becomes the Shi phase, and temperature is warming up to 1150～1210 ℃ from 950 ℃, is the vital stage to containing chromium slag Shi matter brick during this. At first to take the roasting of oxidizing flame atmosphere in a period of time on the low side in temperature, so that the Shi matter brick temperature homogenisation of substance avoids occurring " half-cooked " phenomenon. The second, for guaranteeing Cr VI detoxifcation in-depth, must take the insulation of normal pressure reducing atmosphere at the firing temperature section, kiln atmosphere is controlled at following numerical value: O₂＜1%;CO ₂=15～17%; CO=3～6% is reduced at a low price chromium and at a low price iron to guarantee high valence chrome and high price iron. Its chemical equation is as follows:

In addition, in the Shi matter brick body, contain a large amount of acidic oxide SiO ₂(accounting for 55%).At SiO ₂Under a large amount of conditions that exist, CrO ^-2 ₄Poor heat stability easily is decomposed into tart Cr ^{+ 3}, and same SiO ₂Deng the stable clinopyroxene compounds NaCrSi of generation ₂O ₆Or CaCrAlSiO ₆, and NaCrSi ₂O ₆Or CaCrAlSiO ₆Can form sosoloid with pyroxene, the utmost point is insoluble in water.This is that the present invention fills a prescription and can make one of major reason of chromium residue detoxifying.In this stage, it is 7 hours that low temperature fuses soaking time, and high-temperature holding time is 8～10 hours.The quadravalence section is cooling stage, reduces to room temperature from 1210 ℃, and cooling stage is that the liquid phase cools that occurs in the Shi adobe body is transformed into solid phase-glassy phase stage, is hardened in the glassy phase process in liquid phase cools, simultaneously also Cr ^{+ 6}Reduzate Cr ^{+ 3}Be solidificated in firmly in the glassy phase, cut off with air in the contacting of oxygen, " rise " phenomenon can not appear again.General control of this stage 4～10 hours.

Embodiment one:

The 6 tons of loess plates of weighing, 3.0 tons of chromium slags, 3 tons of grogs, use earlier crusher in crushing, be crushed to 30 orders with pulverizer again, in fragmentation, add 1.5 tons of water, after fully stirring, ageing 2 days, be pressed into 238 * 238 * 52 Shi adobe then with shaper, drying to adobe water content is 3% promptly to deliver in the not board-like small cross-section tunnel furnace of horse and burn till, and burns till the fs to rise to 300 ℃ from normal temperature, heating-up time is 20 hours, subordinate phase heated up the phase III 15 hours from 300～950 ℃, rise to 1150 ℃ from 950, heated up 7 hours, and be incubated 8 hours again, the quadravalence section is reduced to room temperature from 1150 ℃, through 5 hours, just can get qualified product.

Embodiment 2:

Weigh 2.4 tons of loess plates, 1.2 tons of chromium slags, 1.0 tons in grog adds 0.37 ton in water, through broken, be crushed to 30 orders.Ageing 3 days, making 238 * 238 * 52 base substrate drying to water content with shaper then is 3%, delivers to the not board-like small cross-section tunnel furnace of horse and burns till.Fs is 24 hours, and subordinate phase is 22 hours, and the phase III rises to 1210 ℃ with 950 ℃, goes through 7 hours, is incubated 10 hours again, and the quadravalence section is 10 hours.

The physics and chemistry value of products obtained therefrom of the present invention and standard gauge definite value be (seeing Table 1) relatively, be better than setting, and qualification rate reaches more than 95%.

Table 1

Standard physical and chemical project standard gauge definite value Shi brick

Certified products goods of inferior quality Grade A test value

Rupture strength MPa＞3.0＞3.5＞4.0 13.4

Compression strength MPa＞20＞25＞30 41.6

Frost resistance, 25 losss of strength 1.8 of % freeze-thaw cycle

Be not more than 25

Water-intake rate＜10＜9.0＜8.0 9.64

Claims (2)

1, a kind of chromium slag Shi matter brick is characterized in that composition and proportioning are as follows: loess plate: chromium slag: grog=55～65: 17～23: 23～17 (weight percents).

2, a kind of manufacture method of Shi matter brick as claimed in claim 1, its technological process is as follows: raw material → fragmentation → pulverizing → screening → ageing → moulding → drying → fire, the water of adding 6～10% when it is characterized in that broken and pulverizing, pulverized particles to 30 ± 5 orders, adobe is of a size of 238 * 238 * 52 millimeters, adobe is fired at the not board-like small cross-section tunnel furnace of horse, firing temperature is controlled at 1150～1210 ℃, in firing range, be incubated 8～10 hours then, keep the normal pressure reducing atmosphere in the stove.

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