At present, most of the domestic production of NdFeB permanent magnet materials adopts the intermediate frequency induction furnace, and the intermediate frequency induction

The service life of the furnace depends largely on the crucible knotting technology, this crucible knotting method

Directly affects the production efficiency and production cost of the enterprise, most manufacturers have two problems: One is the formula

The ratio is not good, and the second is the unreasonable process. The short crucible life affects the production efficiency and increases production

cost.

The purpose of the present invention is to provide a crucible knotting method with reasonable formula and advanced technology.

The purpose of the present invention is achieved by the following technology:

1. Formula

(M1_xNx), rSzKw

M is 3 # magnesia, its composition is Mg0% ≥87%, Si02≤4%, Ca0≤5%

N is 7 # magnesia

S is water glass, molecular formula: Na2Si03. IOH20

K is refractory mud:

X = o. 25 -0.45 W-4-8

Y -2-4

Z = 0. 5-2

Second, the process

1. Mixing: mix the ingredients according to the mixing ratio and mix well in the mixer

2. Furnace building: put a layer of glass cloth (insulating material) on the inner wall of the induction coil

The refractory is compacted, and then put on the alumina crucible, (note two points: the crucible should be placed in the center as much as possible.

The top of the pot is level with the coil) and then gradually add refractory material, and gradually tighten it with an iron rod from bottom to top.

Seek tight and loose, and then correct the upper surface and furnace mouth.

    3-Bake:

    After the furnace is built, it is placed outdoors, dried for 24 hours, and then placed in an oven to dry at 80-100 ℃

Bake for 5 days and nights before use.

    The following uses non-limiting examples to describe the present invention more specifically and in detail, which will help the present invention and

Understanding of its advantages

    Example one

    Select 3kg magnesia 4kg, 7 # magnesia 8kg, refractory mud 24kg, water glass 4kg,

Stir evenly in the mixer, put the evenly stirred refractory material into the glass cloth lined with the inner wall of the induction coil

On the top, tamped with an iron rod, put it outdoors for 24 hours, and bake in a 90 ° C oven for 5 days and nights before use.

    Example 2

    Use 3 # magnesia 3kg, 7 # magnesia 9kg, refractory mud 25kg, water glass 4.5kg, in the mixer

Stir well and make according to the process of Example 1.