Binder Composition for Fine Mineral Pelletizing
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Solution Overview
Problem
Existing pelletization methods for fine iron ore require high silica content binders like clay minerals, which increase silica content in pellets and can lead to sintering issues, and require significant hydrated lime, causing volume expansion and structural damage during the pelletization process.
Innovation Solution
A binder composition comprising a colloid agent that exerts cohesive forces and a synthetic polymer that disperses mineral particles, reducing the need for silica-based binders and hydrated lime by forming a synergistic effect that enhances the compressive strength of green and dried pellets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If clay minerals are used as binders to achieve sufficient pellet strength, then the adhesive and cohesive forces are improved, but the silica content in the finished pellet increases
Solution Approach 1:
The invention changes the chemical composition parameters of the binder system by replacing clay minerals with a combination of organic binder and inorganic compound. This substitution maintains the necessary adhesive and cohesive forces while reducing the silica content in the finished pellet, directly resolving the contradiction between pellet strength and silica content
Solution Approach 2:
The invention uses a composite binder system consisting of an organic binder (such as starch, cellulose, or lignin) combined with an inorganic compound (such as calcium carbonate or magnesium oxide). This composite approach provides both the mechanical bonding strength needed for pellet integrity and the chemical properties to reduce silica content, thereby resolving the contradiction between these two parameters
2Strength
If calcium oxide is hydrated during the pelletization process to increase mechanical stability, then the cohesive force is improved, but the volume expansion damages the pellet structure
Solution Approach 1:
The invention performs the hydration of calcium oxide in advance, before the pelletization process. By pre-hydrating the calcium oxide to form calcium hydroxide, the volume expansion occurs before pellet formation, avoiding structural damage. The pre-treated binder then provides cohesive force during pelletization without causing harmful volume changes, resolving the contradiction between mechanical stability and volume expansion
Solution Approach 2:
The invention separates the hydration process from the pelletization process into distinct stages. The binder is pre-treated (hydrated) separately, then applied to the ore during pelletization. This segmentation allows the volume expansion to occur independently without affecting pellet structure, while still providing the necessary mechanical stability
3Quantity of substance
If fine mineral particles are used as feed material, then the ore concentration is improved, but the particles pack into a nonpermeable bed and are carried away as dust
Solution Approach 1:
The invention uses a binder as an intermediary substance between fine mineral particles. The binder coats and binds the fine particles together, forming larger agglomerates that maintain the high ore concentration of fine particles while preventing them from packing into nonpermeable beds and reducing dust carryaway, thus resolving the contradiction between ore concentration and permeability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The binder composition improves the compressive strength of pellets and reduces the amount of silica and hydrated lime required, resulting in more stable and efficient pelletization with reduced dust loss and improved permeability in blast furnaces.
Implementation Method 1
a) at least one colloid agent which exerts a cohesive force on the mineral particles forming the pellets
Implementation Method 2
b) at least one synthetic polymer which disperses mineral particles in the pellets
Data Source
AI summary
A process for pelletizing particles of a fine mineral ore, the process comprises the steps ofa) mixing the particles of a fine mineral ore with a binder composition to obtain a pellet feed,b) forming the pellet feed into balls,c) drying the balls to form dried balls,d) preheating the dried balls at 60 to 105° C. until constant weight to form preheated balls,e) subsequently heating the preheated balls to a temperature of 1200° C. to 1400° C. to obtain pellets,wherein the binder composition comprisesa) at least one colloid agent which exerts a cohesive force on the particles of a fine mineral ore forming the pellets, andb) at least one synthetic polymer which disperses the particles of a fine mineral ore in the pellets,wherein the synthetic polymer is a maleic acid/acrylic acid or a maleic acid/methacrylic acid copolymer.