RU2245309C2 - Method for producing of fertilizer from sapropel - Google Patents

Abstract

FIELD: agriculture, in particular, manufacture of fertilizer from silt, sapropel, sewage water sediment.

SUBSTANCE: method involves preliminarily drying basic product in horizontal rotating drum type furnace; separating foreign matter on sorting machine; grinding; introducing additive; mixing and granulating in extruder press. Drying in horizontal rotating furnace is performed at temperature below 240⁰C. Additive is potassium gum with emulsifier, which is introduced in an amount providing molding moisture content of sapropel mass of up to 18-24%.

EFFECT: provision for producing of fertilizer with homogeneous granules having stabilized sizes and kept properties of sapropel.

1 dwg

Description

The invention relates to the production of fertilizers from sludge and the like, in particular, to methods for producing fertilizer from sapropel.

A known method of producing fertilizer from sapropel, which consists in pre-drying, thickening and granulation in the process of spray drying by supplying a coolant. A dry product is subjected to mechanical compaction and running-in during transportation, then it is classified by size (Scientific and Technical Review of Giprorechtrans “Sapropel - Resources, Applications, Production and Processing Technology”, Moscow, 1991, pp. 108-109).

The disadvantages of the method are the difficulty of preliminary cleaning of raw materials, the heterogeneity of the obtained granules by size, which complicates the heat treatment, the drying temperature exceeds 240 ° C, which leads to deterioration of the fertilizer.

A known method of manufacturing granular sapropel, which consists in transporting partially dehydrated (up to 80-85%) sapropel to the hopper, pre-drying on a conveyor belt by contact and convective heating and final drying of the granules in a fluidized bed under a vibrating air distribution grill to the required humidity. If necessary, an installation is added for sorting granules (drum screen) and a hopper for receiving them (see ibid. P.106-107).

The disadvantage of this method is the inability to obtain granules due to the presence of heterogeneous inclusions (pebbles, shell rock, plant inclusions).

A known method of producing fertilizer from sapropel, including pre-drying in a horizontal rotary kiln of a drum type, separating foreign inclusions on a sorting machine, grinding, introducing additives, mixing and granulating in a press extruder (see RF patent No. 2041866, class C 05 F 7 / 00, 08.20.1995). This method is the closest to the proposed problem and the way to solve it.

The disadvantages of this method are the loss in the technological process of part of the nutritional properties of natural sapropel and the lack of dimensional stability of the obtained granules, which complicates the accuracy of dosing when applied to the soil, and the associated excessive consumption of fertilizer.

The invention is aimed at obtaining uniform granules with stable sizes, preserving all the properties of natural sapropel and eliminating the excessive consumption of fertilizer when it is applied to the soil.

This is achieved by the fact that in the method of producing fertilizer from sapropel, including pre-drying in a horizontal rotary kiln, separating foreign matter on a sorting machine, grinding, introducing additives, mixing and granulating in a press extruder, according to the invention, drying in a horizontal rotary kiln type is produced at a temperature not exceeding 240 ° C, and as an additive, potassium humate with an emulsifier is used, which is introduced in an amount that ensures the molding sapropel ground mass content up to 18-24%.

The invention is illustrated by the technological scheme, where it is indicated:

1 - cultivator for crushing the source sapropel;

2 - box feeder;

3 - belt conveyors;

4 - rotary kiln continuous type drum;

5 - noriya;

6 - sorting machine;

7 - core mill;

8 - pneumatic conveyor;

9 - a cyclone;

10 - mixer;

11 - a container for storing potassium humate;

12 - pump for feeding potassium humate;

13 - container-dispenser of finished products.

A method of manufacturing a granular sapropel is as follows.

Sapropel is loaded into a ripper 1, in which the raw materials are crushed to lumps with a diameter of up to 50-70 mm. The crushed sapropel with a box feeder 2 is fed to the conveyor belt 3 and immersed in the loading chamber of a continuous rotary drum type 4 furnace, in which the heat carrier and sapropel move in the same direction. The drying temperature should not exceed 240 ° C to avoid the decomposition of sapropel. In the furnace 4, sapropel is crushed and dried during movement to a moisture content of 12-15%.

Using a conveyor belt 3 and elevator 5, the sapropel is fed into a sorting machine 6, which consists of three tiers of horizontally arranged sieves, which, due to constant directional shaking, advance the material, while sorting it by fractions. The result is the separation of foreign inclusions.

The purified sapropel is fed to a core mill 7, where the material is milled to a fraction of 40-100 microns.

To prevent air pollution by dust particles of sapropel, an aspiration system is provided, consisting of sealed air ducts of the pneumatic conveyor 8 and cyclone 9. When unloading, the dusty sapropel is wetted with steam.

Then the sapropel is fed into the mixer 10, into which at the same time the required amount of potassium humate and emulsifier are dosed from the tank 11 by the pump 12. In the mixer 10, a homogeneous mass of sapropel molding moisture of 18-24% is formed. The finished mass of sapropel is fed into the chamber of the press extruder 13, passed through special dies and granules with a diameter of 3 mm and a length of 5-6 mm are obtained, which are conveyed by conveyor 3 into the hopper of the dispenser 14 and packaged.

The fertilizer granules obtained by the proposed method have a uniform composition, preserve all the nutritional components of natural sapropel and, due to the stability of their sizes, make it possible to achieve high accuracy of the required dosage when they are applied to the soil.

Claims (1)

A method of producing fertilizer from sapropel, including pre-drying in a horizontal rotary kiln of a drum type, separation of foreign inclusions on a sorting machine, grinding, introducing additives, mixing and granulation in a press extruder, characterized in that drying in a horizontal rotary kiln of a drum type is carried out at a temperature not higher than 240 ° C, and as an additive, potassium humate with an emulsifier is used, which is introduced in an amount to bring the molding moisture to the ground mass sapropel up to 18-24%.