JPS6321275A - Binder for granular fertilizer - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention is applicable to granulating agents for granular fertilizers, granulating agents for agricultural chemicals, and the production of briquettes made from slag by-products of the iron and non-ferrous metal industries. This invention relates to a granulating agent with good disintegrability such as a binder used.

(Conventional technology) Conventionally, when producing granular fertilizer from slag by-product of the iron and non-ferrous metal industry, the granulating agent used therein was a neutralized sulfite pulp wastewater produced as a by-product from the sulfite pulp manufacturing process. and blackstrap molasses are used either alone or in combination in various proportions.

The amount of the granulating agent added was such that the solid content of the granulating agent was approximately 4 to 10% of the solid content of the material to be granulated, and granulation was performed using a pan-type granulator or the like. Then, dry it using a rotary dryer.

Regarding the performance of the slag granular fertilizer produced in this way, disintegration in water and soil is particularly desired from the viewpoint of fertilizer effect.

This disintegration in water and soil is specified in the granular fertilizer test method, and the disintegration test in water is such that 50 grains of granular fertilizer with a diameter of 2,000 microns or more are 80% in water within 24 hours.
0% or more disintegration and dispersion, and in the soil disintegration test, the same granular fertilizer used in the water disintegration test was used at a moisture content of 60%.
% of soil and disintegrate by 80% or more in 7 days.

The above-mentioned slag granular fertilizer using neutralized sulfite pulp waste liquid, waste molasses, etc. as a granulating agent does not fully satisfy these requirements.

Therefore, it is an important issue to find a binder that improves the disintegration properties of granular fertilizers in water or soil.
An example of this can be seen in 88. According to this, [in a fertilizer that uses high basic steel slag as a raw material and adds or mixes a granulating binder to it and makes it into granules, by adding polyoxy alkylene alkylphenyl ether sulfate, it is possible to "Highly basic steel slag granular fertilizer characterized by improved disintegration and dispersibility in soil." The granulating binder described herein is a neutralized product of sulfite pulp waste liquid or blackstrap molasses. The present inventors attempted to solve the problem by means different from the method described in JP-A-60-16888.

[Problems to be solved by the invention]

As mentioned above, what is particularly desired for slag granular fertilizers is disintegration in water and soil.

Depending on the type, conventional granular fertilizers exhibit some level of disintegration and dispersibility immediately after production to 11 months, but after a long period of time of 3 months to 6 months, the disintegration properties are extremely reduced. Alternatively, there are problems such as not exhibiting disintegration properties even immediately after production, and it is an important issue to discover a binder that has granulation action and disintegration properties.

[Means to solve the problem]

In order to solve the problems of conventional slag granular fertilizers, the inventors of the present invention conducted extensive research on granulating agents for slag granular fertilizers, and as a result, they were able to maintain disintegration in water and soil over a long period of time. We have developed an excellent granulating agent for slag granular fertilizers that has both the effect of a binder and a granulating agent.

The present inventors took note of the composition of the sulfite pulp effluent, which is a by-product from the zulfite pulping process, and found that by over-treating the sulfite pulp effluent, the genin sulfone in the effluent was By removing the high molecular weight part of the acid salt and using the obtained low molecular weight part as the main component, an excellent slag granular granulating agent for fertilizer was obtained.

The fractionation membrane used in ultrafiltration has a molecular weight cutoff of 2.0.
A range of 00 to ioo, ooo is preferable.

Although it is possible to use a membrane with a molecular fraction i of 2,000 or less, it is not economical in terms of productivity and yield.

When a membrane with a molecular fraction of 1ioo, ooo or more is used, the removal efficiency of the polymer portion of the genin sulfonate in the sulfite pulp wastewater is poor, and the performance as a granulating agent for slag granular fertilizers is not satisfactory.

The pH of the ultrafiltrated permeate can be adjusted by a known method, and the more alkaline the pH, the better the disintegration properties tend to be.

[For production]

The components of slag used for granular fertilizer vary depending on the type of furnace, but include CaO.

S i 02 , MgO, Δ1203. Fed,
It contains MnO, etc., and has the property of gradually combining at room temperature due to the presence of free lime, etc., to create insoluble calcium monosilicate (pozzolanic reaction). This property was the reason why the disintegration property could not be sufficiently satisfied when conventional binders were used.

Although the mechanism by which the present invention achieved the disintegration property is not clear, it is presumed from the above-mentioned reasons that the permeate portion obtained by ultrafiltration of the zulfite pulp cooking effluent suppresses the pozzolanic reaction. This seems to be because it has some kind of effect.

(Effects of the Invention) The effects of the present invention are very advantageous in the following points compared to conventional binders for granular fertilizers.

(1) Granulation is possible with a smaller amount added than before, and inexpensive granules can be obtained.

(2) By making it possible to significantly improve disintegration properties in water,
Fertilization effect can be promoted.

(3) Disintegrability can be maintained for a long period of time.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto.

The sulfite pulp cooking effluent has a molecular weight cutoff of 20,000.
and 100,000 ultrafiltration membrane, and the permeate was used as a binder and added in a predetermined amount to the material to be granulated, granulated, and then dried at 100 to 300°C.

The disintegrability of the obtained granules in water and the amount of binder added required for granulation are shown in the table below.

Note that here, blast furnace slag (A) and converter slag (B) were used as the materials to be granulated.

Table 1 Results of water disintegration test From Table 1, it is clear that the product of the present invention has a smaller additive amount and is superior in water disintegration than conventional binders.

Claims (3)

[Claims] (1) Ultrafiltration of sulfite pulp cooking waste liquid,
A granulating agent with good disintegration properties whose main component is the permeate part. (2) Ultrafiltration treatment has a molecular weight cutoff of 2,000 to 100,
Granulating agent according to claim 1 using a 000 fractionation membrane (3) The granulating agent according to claim 1 or 2, wherein the ultrafiltration treatment is adjusted to pH 3 to 10.