Process to produce manganese pellets from non-calcinated manganese ore and agglomerate obtained by this process
It is described a manganese pellet production from non-calcinated manganese ore, comprising the following phases: (a) ore size preparation through ore classification by function of particle size, smaller or equal to 1 mm particles being maintained from the ore particle fraction process so as to have a smaller or equal to 1 mm size, as well as the comminution of these particles; (b) flux addition; (c) agglomerant addition; (d) pelletizing resulting in crude pellets; and (e) thermal processing through crude pellet drying, pre-heating and heating.
1. A process to produce manganese pellets from non-calcinated manganese ore comprising:
ore size preparation through ore classification by particle size smaller or equal to 1 mm particles and comminution of the particles;
flux addition;
agglomerant addition, wherein the agglomerant is selected from a group consisting of bentonite at 0.5% to 2.0% by mass, hydrated lime at 2.0% to 3.0% by mass, carboximetilcelulose (CMC) at 0.05% to 0.1% by mass, and mixtures thereof;
pelletizing resulting in crude pellets; and
thermal processing through drying, pre-heating and heating the crude pellets.
2. The process according to claim 1 , wherein an ore drying phase occurs before the ore size preparation phase to dry the ore to a maximum moisture of 9% by mass.
3. The process according to claim 1 , wherein the comminution comprises crushing and pressing operations.
4. The process according to claim 3 , wherein during the ore size preparation, a fraction of manganese ore with particle size greater than or equal to 1.0 mm is handled with a roller press.
5. The process according to claim 1 , wherein the ore size preparation results in ore particles comprising a specific surface area between 800 to 2000 cm 2 /g.
6. The process according to claim 1 , wherein the ore size preparation results in 40 to 60% by mass of ore particles having a size smaller than 0.044 mm.
7. The process according to claim 1 , wherein the flux addition comprises adding calcite limestone, dolomite limestone, mixtures of calcite and dolomite limestone, or other magnesium oxide source.
8. The process according to claim 1 , wherein the crude pellets have a minimal resistance of 1 and 2 kg/pellet and a resilience of at least 5 drops.
9. The process according to claim 1 , wherein the thermal processing comprises passing the crude pellets through a traveling grate, grate kiln or steel belt-type furnace.
10. The process according to claim 9 , wherein the thermal processing is at a maximum temperature of 1280 to 1340° C.
11. The process according to claim 9 , wherein the thermal processing has a total time ranging from 34 to 42 minutes.
12. An iron-manganese agglomerate obtained through the process of claim 1 , wherein the iron-manganese agglomerate comprises an average diameter between 8 and 18 mm, and wherein the iron-manganese agglomerate comprises a minimal compression resistance of 250 daN/acclomerate.
13. A process for producing manganese pellets from non-calcinated manganese ore comprising:
ore size preparation through ore classification by particle size smaller or equal to 1 mm particles and comminution of the particles, wherein the ore size preparation results in 40 to 60% by mass of ore particles comprising a size smaller than 0.044 mm;
flux addition;
agglomerant addition of bentonite at 0.5% to 2.0% by mass;
pelletizing resulting in crude pellets; and
thermal processing through drying, pre-heating and heating the crude pellets.