Vertical roller mill production of fly ash application domain analysis

Fly ash is the thermal power plant burning a kind of industrial waste discharge of the pulverized coal fired boiler. Our country is rich in coal resources, the development of modern electric power industry is still dominated by coal-fired power. The total amount of thermal power plant ash discharge in 1985 37680000, to 99360000 in 1995, an average annual increase of 5600000. According to the current coal, to the national average calculation, every increase 10MW capacity per year increase of nearly million tons of fly ash emissions, in 2000 coal emissions reached 160000000 t. Fly ash is mainly used in building materials, construction, road construction, backfilling, agricultural and resource recycling and other aspects. Fly ash concrete: fly ash concrete is widely used in civil engineering, (including water conservancy project), construction engineering and precast concrete products and parts are widely used. Through the application of fly ash in concrete, properties of basic research, engineering and so on, to further understanding of fly ash "shape effect", "activity", "micro aggregate effect", must pay full attention to in the application of technology, in order to control and guarantee the quality of fly ash concrete, at the same time also confirmed the application of fly ash in concrete in the "negative factors" and "variability". Only the development of fly ash products and selected in line with the requirements of the quality of the raw fly ash in concrete, and rational use, in order to meet the quality of various types and different grades of concrete requirements.

Characteristics of fly ash embankment engineering, the first is of less investment, quick start, the use of fly ash in building materials products like that, to spend more to invest and build factories. Embankment and backfill, as long as the ash and paving, rolling machine, can carry out construction. Followed by the use of ash content, such as Shanghai Hujia Expressway Embankment, according to 2? 7m, road 26m, can be used wet ash per kilometer is about 100000 t. This amount is equivalent to an annual output of 100000 t in aerated concrete plant ash, or the equivalent of an annual output of 1? 500000000 of fly ash sintered brick with ash content. Once again, the quality is not as strict ash used in cement, concrete, whether it is dry ashing, wet ash can be used. Fly ash products: ash products can be divided into non burning and non burning type, firing fly ash building. With the use of fly ash volcano ash activity, combined with calcium containing compounds, and the reaction in a certain temperature, humidity, generate the hydration products and get a certain strength and other performance. This kind of product manufacturing process strict, equipment is more complicated, in which each product and each has its own characteristics. Their different conditions, quality requirements and the amount of fly ash is also different, and the application of technology, the requirements of different products also have their own characteristics.

Fly ash fired building products instead of part of clay brick, hollow brick, brick and sintered fly ash ceramsite with fly ash, adding fly ash production of ceramic products, is a new type of building material is very promising. Application of fly ash in agriculture: the fly ash is mainly composed of coarse particles (0.25 ~ 0.01mm) and fine particles (0.005 ~ 0.001mm). The structure of fly ash particles determines compared with soil moisture, ash water more easily utilized by plants. Those characteristics in agriculture obtained the full affirmation. The addition of fly ash on soil improvement, nursery, covering the winter crops, made by fly ash as silicon calcium fertilizer, humic acid, and the magnetized fly ash mixed fertilizer, ash field soil reclamation, fly ash filling potholes and mining area subsidence area reclamation and other significant effect. Further utilization of fly ash: fly ash is a mixture of hollow glass and other components, including glass beads, silica alumina carbon in the vitreous, porous carbon particles and debris like carbon in iron rich glass beads. Morphology, density and composition are different particles, utilization and economic value are not the same. Therefore they are separating from the fly ash or extracted through chemical or physical method, achieve the best, although the cement consumption is small, but the value in use of fly ash is higher, so called fine use, also known as the high value added utilization. Fly ash is an important resource, contains a variety of elements, therefore, fly ash utilization projects are fine, the project development abroad is not less, but can really into productivity, but also can persist much. China has research and development projects are: fly ash floating beads, beads and the precipitation separation; separation and utilization of carbon in fly ash; fly ash separation of iron rich glass beads and using fly ash and aluminum extraction and so on.