GB2025832A

GB2025832A - Apparatus for Pelletizing Titanium-bearing Particulate Material

Info

Publication number: GB2025832A
Application number: GB7830547A
Authority: GB
Original assignee: V NI I PI TITANA; ZAPOROZH TITANO MAGNIEVY KOM
Current assignee: V NI I PI TITANA; ZAPOROZH TITANO MAGNIEVY KOM
Priority date: 1978-07-20
Filing date: 1978-07-20
Publication date: 1980-01-30
Also published as: GB2025832B

Abstract

A power-driven drum 1 rotating about horizontal axis is divided into successively disposed and intercommunicating chambers: a non- watering chamber 4 wherein feed material to be agglomerated is introducted via inlet 2 together with a sticky mix, a watering chamber 5 sensed by spray nozzle 7 wherein the mixed and aggregated feed material is pelletized to a predetermined size, and at least four succeeding non-watering chambers 6 (only two illustrated) wherein the pellets are compacted and further increased in size. The watering chamber 5 and the succeeding non-watering chamber 6 are equal in length, l. The length of the first non-watering chamber 4 is 2 to 2.5 times the length l which permits the feed material to be introduced into the first chamber 4 in the dry state. <IMAGE>

Description

SPECIFICATION Apparatus for Pelletizing Titanium-bearing Particulate Material The present invention relates to apparatus for pelletizing titanium particulate material such as beneficated titanium ores and their derivatives, e.g. titanium slags, particularly for making pellets of high impact strength and of uniform size.

For example, there is known an apparatus (cf U.K. Patent Specification 975, 135) which is made in the form of a drum having a charging inlet and a discharge outlet and divided into localized sections or regions a first non-watering region wherein a finely divided material to be pelletized is introduced together with a sticky mix, a watering region wherein the feed material is pellitized with the aid of binder a predetermined size, and a second non-watering region wherein the pellets are compacted to a desired strength and further increased in size. A finely divided material and a sticky mix are introduced into the first region of the drum; the pellets then flow into the next watering region wherein they are rolled while water is added thereto in an amount sufficient to wet surfaces of the pellets for adherance of additionally finely divided material.The pellets are wetted in every succeeding watering region, starting from the first watering region of the drum. As the pellets grow in size they are moved along the drum. The undersized pellets are recycled into the aforesaid first localized region of the drum.

The apparatus referred to above suffers from a number of disadvantages. For example, the pellets produced by this apparatus have insufficient compact strength due to the fact that the finely divided material is introduced into the first localized non-watering region of the drum together with a sticky mix which prevents the formation of micro pellets (fine fractions) required for dry adhesion between the material being pelletized and a carbonaceous reducer. In addition, the admixture of finely divided dry material to the region following after the first nonwatering region increases returns of undersized pellets. Due to a broad range of particle sizes, from 20 to 225 mm, the output of undersized pellets is increased and the compact strength of the finished pellets is diminished, thus impairing production efficiency of the apparatus as a whole.

Uncontrolled supply of a binder, having no definate compact strength, onto the dry feed material lowers the impact strength of the pellets produced, brings down the production efficiency of the apparatus and complicates the production of pellets of a predetermined size. Moreover, the apparatus construction fails to provide the introduction of a dry feed material and its complete wetting with a sticky mix prior to being pelletized.

What is desired is apparatus of higher production capacity, wherein the number of chambers and the constructional arrangement thereof enable the production of pellets of uniform size and of higher impact strength.

The invention provides an apparatus for making pellets from titanium-bearing ores and their derivatives, comprising a drum having a charging inlet and a discharge outlet, rotating about horizontal axis and divided into the following successively disposed and intercommunicating chambers: a first-nonwatering chamber wherein a feed material to be balled up is introduced together with a sticky mix, a watering chamber wherein the feed material is balled up with the aid of a binder to a predetermine size, a second non-watering chamber wherein the balls or pellets are compacted to a desired strength and further increased in size, wherein, according to the invention, the second non-watering chamber and the watering chamber have equal lengths, and there are provided not less than four of said nonwatering chambers with the total number thereof being selected in accordance with the requirements to obtain balls or pellets of uniform size and of a high-compact strength, the length of the first non-watering chamber being 2 to 2.5 times the length of any other two chambers, thereby permitting the aggregated feed material to be obtained in the first non-watering chamber in dry state.

Such apparatus construction permits the feed material to be aggregated in; the first nonwatering chamber (into micro-pellets) due to adhesion of the finely divided slag with porous particles of coke, as the mix obtained travels a longer way through the first non-watering chamber, being elongated for the purpose.

In addition, the apparatus construction makes it possible to obtain high strength pellets owing to the fact that the pelletizing procedure continues until completion in two or more succeeding chambers after a binder has been admixed with the pellets.

The apparatus has high production capacity, attained owing to the reduction in the amount of fines recycled in the operating process.

The invention will be further described, by way of example only, with reference to the accompanying drawing in which there is schematically shown in apparatus for making pellets from titanium-bearing material.

Referring to the drawing, the apparatus comprises a drum 1 having a charging inlet 2 and a discharge outlet 3, rotating about horizontal axis and divided into the following successively disposed and intercommunicating chambers: a first non-watering chamber 4 wherein the feed material to be pelletized is introduced together with a sticky mix, a watering chamber 5 wherein the feed material is pelletized with the aid of a binder to a predetermined size, a second nonwatering chamber 6 wherein the pellets are compacted to a desired strength and further increased in size, and further non-watering chambers 6 (only one of which is shown). The second non-watering chamber 6 and the watering chamber 5 are equal in length.There are provided not less than four non-watering chambers 6, with the total number thereof being selected in accordance with the requirements to obtain pellets of uniform size and of high compact strength. The length of the non-watering chamber 4 is 2 to 2.5 times the length 1 of each of the succeeding chambers 5 and 6, thereby permitting feed material to be obtained in the first nonwatering chamber 4 in an aggregated dry state.

Extending through the discharge outlet 3 is a spray nozzle 7 adapted to supply a binder material in a counterflow to the feed material passing to the watering chamber 5. The discharge outlet 3 the drum 1 is provided with a cylindrical screen attachment 8 rotating together with the drum and intended for the removal of fines through its perforations.

The apparatus described above in the following manner, being set in to operation when in the state such as shown in the drawing.

Titanium slag and petroleum coke are fed through the charging inlet 2 of the powerdriven rotating drum 1 into the non-watering chamber 4.

After passing through the elongate chamber 4, the mixed and aggregated material enters the watering chamber 5 upstream of a sulphite-pulp liquor flow, which permits pellets to be obtained with a permissible moisture content. The liquor is fed by the spray nozzle 7 arranged or located in the watering chamber 5, thereby enabling the pellets to agglomerate to a predetermined size (from 5 to 35 mm.). In the watering chamber 5 the mixed material is wetted by the binding liquor and then passed through the succeeding nonwatering chambers 6, wherein it is formed into pellets compacted in strength and growing in size.

Upon passing through the last non-watering chamber 6, the feed material is fed through the discharge outlet 3 onto the cylindricai screen attachment 8 wherein fines are removed and the wetted pellets are delivered for drying.

Example Charged into the non-watering chamber 4 are 5 to 7 tons of titanium slag of which 92 per cent has the size fraction of less than 0.1 mm, and petroleum coke of which 80 per cent has the size fraction of less than 0.15 mm. From the nonwatering chamber 4 the aggregated feed material is passed to the watering chamber 5 in countercurrent relation to the flow of sulphitepulp liquor (with a density of 1.15 to 1.17 g/cm3) fed by the spraying nozzle 7 (500 to 650 kg). In the watering chamber 5 the aggregated feed material is wetted with the binder and then passes through the succeeding four of more nonwatering chambers 6 wherein it is additionally pelletized and compacted in strength.

The rate of throughput of feed materials in dry state (slag and coke) is 1000 kg/h, that of sulphite liquor is 65 kg/h, and the speed of rotation of the drum 1 is 17 rev/min.

Pellets of the following fraction composition have been obtained on the meshed attachment 8 from above 5 to above 20 mm, 70 per cent from above 25 to above 30 mm, 5 per cent from above 20 to below 25 mm, 15 per cent from above 35 to below 40 mm, 2 per cent.

The pellets obtained, depending upon the size and drying technique used, have a compact strength ranging from 20 to 175 kg per pellet.

Claims

1. Apparatus for pelletizing titanium-bearing particulate material, comprising a drum rotatable about horizontal axis and provided with a charging inlet for particular feed material and a discharge outlet for pellets, and partitions adapted to partition the drum into a first nonwatering chamber for mixing feed material introduced therein, a watering chamber for receiving the mixed feed material and pelletizing it with the aid of a binder to a predetermined size, and at least four further non-watering chambers wherein the pellets are compacted to a desired strength and further increased in size, the chambers being disposed successively and intercommunicating with one another, the length of the watering chamber and the length of the following non-watering chamber being equal, the length of the first non-watering chamber being 2 to 2.5 times the said length.

2. Apparatus as claimed in claim 1, substantially as described herein with reference to the accompanying drawing.