JPS6096592A - Pelletization of powdery magnesia lime and powdery calcium carbonate - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method suitable for granulating powdered magnesia and calcium carbonate.

In general, powdered magnesia lime and calcium carbonate have adhesive and agglomerative properties and poor fluidity, so even if you try to use it as fertilizer by spreading it on fields with a spreader, it will not be possible to spread it smoothly. Moreover, even if sprayed forcibly, there are inconveniences such as the spray being scattered by the wind, scattering and falling on workers, or being washed away by rainwater after spraying. Therefore, in the past, attempts have been made to granulate powdered magnesia lime and calcium carbonate by transfer granulation method or extrusion granulation method, but these granulation methods cannot produce granular products. It is necessary to add 10% or more of a binder so that it has the strength to withstand handling, and the granular product becomes too strong and has poor disintegration after spraying, reducing its effectiveness as a fertilizer. There is a problem.

The present invention was made with the aim of solving the above-mentioned problems. Powdered magnesia and calcium carbonate are used in a granular form that is strong enough to withstand handling and disintegrates within 24 hours when exposed to water. The purpose of the present invention is to provide a method for granulating powdered magnesia lime and powdered calcium carbonate that can be molded into products.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The device shown is a so-called rotary roll briquetting machine, and the support member (2) installed on the base (1) has a diameter of 150 KM and a width of 140 m1j.
It has a cylindrical shape with a diameter of 4 mm on the surface. Byttm,
Two rolls with many four parts of depth 1.2 (3)
(4) are arranged on the left and right at a required interval and are mounted so as to be rotatable in the vertical direction. One roll (4) is moved by the cylinder (5) to the other roll (3).
). Also, roll (
3) A funnel-shaped hopper (6) is fixedly arranged directly above between (4), and a screw (7) with an inverted conical outer shape is installed inside the hopper (6). Screw (7
) is rotated by a motor (8).

(9) is a roll drive device installed on the base (1).

Next, we will discuss the granulation method of powdered magnesia.The bulk density is 0.84, the moisture content is 2.3-2.7%, and the size is 297.
Powdered magnesia of less than pin is charged into a batch type muller wheel type mixer (not shown) and water is added to 0.
After adding 5% and 1.5% of molasses as a binder and kneading, this mixture was charged into the hopper (6) of the briquetting machine shown in the figure, and then the mixture was kneaded by the drive of the motor (8). Rotate the screw (7) to push the kneaded material between the rolls (3) and (4), and at the same time, extend the cylinder (5) to push the roll (4) in the direction of the roll (3). When the drive device (9) is driven to rotate the rolls (3) and (4) in the direction of the arrow, the rolls (
3) (4) The kneaded material pushed between the rolls (3)
(4) It is compressed and a plurality of particles are released in a string of beads. The beads are separated into individual granules by a vibrating two-stage granulator (not shown), and these granules are dried at a temperature of 150 to 180°C for about 15 minutes in a dryer (not shown). When the moisture content is set to 0.5% or less, granular magnesia lime having a particle size of 3 to 5 yxm and a crushing strength of 0.8 to 1.5 kF can be obtained. The granular product thus obtained was placed on a mesh with a mesh size of 2 mm, and the temperature was 5 to 25°C.
A disintegration test was conducted on the granular products five times by immersing them in water, and in each test, the granular products disintegrated within 2 to 3 minutes after immersion in water, turned into powder, and settled under the net. From this, it can be seen that the granular product produced by the above granulation method quickly disintegrates and becomes powder when exposed to water.

Also, to describe the granulation method of powdered calcium carbonate, bulk density o, ss'4, moisture content 0.1%, size 210
Powdered calcium carbonate with a particle size of less than μm was charged into a muller wheel type kneader (not shown) in the same manner as the powdered magnesium, and 4% water and 1.5% molasses were added and kneaded. After shaping into beads with the briquetting machine shown in the figure, separating them into a large number of granules using a rectifier, and drying these granules with a dryer to reduce the moisture content to 0.5% or less, the particle size is 3 to 5 fl. Granular products with a crushing strength of 1.5 to 2.9 can be obtained. When this granular calcium carbonate product was subjected to the same disintegration test as magnesia lime, the same results as magnesia lime were obtained.

In addition, for r Rolls (3) (4) etc. using the gravity fall method.
) may be a simple type that is inserted between the two.

As is clear from the above explanation, the present invention involves kneading powdered magnesia lime with the addition of 1.5% or less of a binder, granulating it by applying it to a briquerating machine, and then force-drying it. Since it is solidified, the granulated magnesia lime etc. according to the present invention has a crushing strength of 0.8 to 1.5 kf.
Not only can it withstand handling well, but it also has excellent effects such as disintegrating quickly when exposed to water, making it suitable for use as fertilizer.

[Brief explanation of the drawing]

The drawing is a perspective view of a rotary roll briquetting machine used to carry out the present invention.

Claims (1)

[Claims] Approximately 1.5% powdered magnesia or powdered calcium carbonate
After kneading it with the following binder, it is made into granules with a size of about 3 to 5 mm using a rotating roll briquetting machine, and then the granules are force-dried to a moisture content of 0.5% or less. A method for granulating powdered magnesia and powdered calcium carbonate, which is characterized by solidifying powdered magnesia.