The subdivisional works shall be divided according to the structural composition or section of the industrial furnace: when the masonry work quantity of the industrial furnace is less than 100m 3, one furnace can be regarded as a sub project, or two or more parts or sections can be combined into one sub project; the sub project shall be divided according to the industrial furnace's pedestal (platform). The larger divisional works can be divided into several sub divisional works; the unit works should be divided into industrial furnace masonry works of an independent production system (or industrial furnace masonry works in an industrial building). The larger unit project can be divided into several sub unit projects.

The sub projects are usually divided according to the structure or section of the industrial furnace. For example, general industrial furnace masonry engineering can be divided into furnace bottom, furnace wall, vault and other sub projects. The blast furnace can be divided into sub projects according to the bottom, hearth, bosh, waist, shaft and throat. The primary reformer is divided into sub projects according to radiation section, transition section, convection section and gas transmission main pipe. However, considering the small amount of masonry work of some industrial furnaces, the division should not be too detailed to avoid tedious. For example, for industrial furnaces with masonry quantities less than 100 m3, the masonry works of one furnace can be regarded as a sub project. Such as a mixer car, a heat treatment furnace, an aluminum reduction cell, etc. Two or more parts or sections can also be combined into one sub project. Such as furnace bottom and wall of heating furnace, preheating section, heating section and cooling section of rotary kiln.

Each industrial furnace masonry work shall be a part of the project. Such as a heating furnace, a rotary kiln, a cracking furnace, etc. However, for furnaces with large amount of masonry work, the whole masonry work should be divided into a part project. For example, the blast furnace body and each hot blast stove body (usually equipped with 3-4) are divided into several sub projects.

The masonry works of industrial furnaces in an independent production system are divided into unit works, or the masonry works of industrial furnaces in an industrial building are regarded as unit works, such as: masonry works of blast furnace and its auxiliary equipment, masonry works of all aluminum reduction cells (dozens to 1200 sets) in aluminum electrolysis workshop, masonry works of all industrial furnaces in steel rolling workshop, etc. The masonry works of all industrial furnaces in the steel rolling workshop include the following situations: for example, there are several soaking furnaces in the rolling workshop; there are several heating furnaces in the hot rolling workshop; there are two heating furnaces and four heat treatment furnaces in a thin plate workshop, and their masonry works are regarded as a unit project.

In an independent production system, when the industrial furnace masonry work quantity is less than 500m? 3, the industrial furnace masonry engineering can be regarded as a divisional project, together with other industrial installation works as a unit project. In view of the fact that some industrial furnaces are key thermal equipment and the quality requirements of their masonry works are very strict, it is not convenient to merge them into a unit project with other industrial installation projects. In recent years, more and more extra large blast furnaces and coke ovens have been built. The total amount of refractory materials required for a furnace is 20000-30000 tons, and the division of furnace building projects is different from the usual method. For example, the furnace building project of a company with a furnace capacity of 4063m3 is divided into 12 unit projects.

In addition to the construction of blast furnace and coke oven, the masonry works of other industrial furnaces are not particularly large, but there are also many types of furnaces with masonry quantities greater than 500 m 3. For example, the total amount of refractory required for a large walking beam furnace is over 3000t, the annular furnace is more than 2000t, the carbon roasting furnace is more than 7000t, the glass furnace is more than 5000T, and the continuous vertical furnace is more than 3000t