Ecological Refractory Binder System Reducing Benzo(a)pyrene
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Solution Overview
Problem
The refractory materials used in steelmaking often contain hazardous carcinogenic compounds, such as aromatic polycyclic hydrocarbons, which pose environmental and health risks, and existing binder systems for tap hole closure in Blast Furnaces lack adequate mechanical resistance and workability for efficient injection and safety.
Innovation Solution
A new binder system is developed using modified coal-tar pitch, anthracene oil, soybean oil, biopitch, paraffin, dextrin, and vegetable butters, processed through specific distillation and mixing to reduce benzo(a)pyrene concentrations and improve mechanical properties, incorporating additional organic compounds like phenolic resins and furane resins for enhanced performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional binder systems based on coal-tar and phenolic resins are used, then adequate workability and mechanical resistance are achieved, but high concentrations of carcinogenic aromatic polycyclic hydrocarbons are present
Solution Approach 1:
The patent develops a composite binder system combining modified coal-tar pitch (with reduced carcinogenic content through controlled distillation) with vegetable oils (soybean, linseed, castor) and organic compounds. This composite approach maintains the workability and mechanical resistance of conventional systems while significantly reducing benzo(a)pyrene concentrations from 12,000 ppm to below 600 ppm.
Solution Approach 2:
The patent applies parameter changes by controlling the distillation process of coal-tar to achieve specific temperature ranges and final compositions. The modified pitch is produced with precise benzo(a)pyrene concentration control (<600 ppm) while maintaining adequate viscosity and reactivity for binder performance.
2Object-affected harmful factors
If modified coal-tar pitch with reduced carcinogenic content is used, then environmental and health safety is improved, but workability and mechanical resistance may be compromised
Solution Approach 1:
The patent combines modified coal-tar pitch with vegetable oils (soybean, linseed, castor oil) and organic compounds to create a composite binder system. The vegetable oils compensate for any workability losses from the modified pitch while the organic compounds enhance mechanical resistance, achieving both safety and performance goals.
3Strength
If rapid polymerization reaction is initiated for interim curing, then mechanical resistance is improved soon after injection, but workability time may be reduced
Solution Approach 1:
The patent employs a two-stage binding mechanism: first, the modified pitch provides initial workability for injection; second, upon exposure to hot metal, the pitch undergoes controlled polymerization to form a refractory mass. This periodic action sequence ensures adequate workability time followed by rapid strength development when needed.
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 new binder system achieves reduced carcinogenic compound concentrations, improved workability, and sufficient mechanical resistance, ensuring safe and efficient tap hole closure with reduced environmental and health impacts.
Implementation Method 1
distill coal-tar with a concentration of benzo(a)pyrene in the order of 12,000 ppm at a temperature around 180° C. to get a tar with a high content of benzo(a)pyrene; submit the tar obtained in stage a) to fractional distillation at temperature of 470° C.+/−20° C. to get a modified pitch with a concentration of benzo(a)pyrene of 600 ppm or less
Implementation Method 2
developing an interim curing or polymerization reaction, seeking to guarantee the operational safety of the tap hole area after removing the injection gun from the pig iron tap hole
Implementation Method 3
mixing the pitch obtained with other raw materials such as vegetable oils, vegetable tar and organic compound additives
Data Source
AI summary
The invention presented here deals with getting one of the raw materials of a new refractory binder system, the modified coal-tar pitch starting with heating the coal-tar, according to the specific distillation curve, later reaching a final distillation temperature of around 470° C., resulting in getting a final compound with a concentration of benzo(a)pyrene in the order of 600 ppm, together with the mixture of other raw materials for the composition of the binder system, such as anthracene oil (AO), soybean oil, linseed oil, castor oil, diesel oil, rapeseed oil, biodiesel, biopitch (Vegetable tar), paraffin, dextrin (corn starch), stearine, paraffin, vegetable waxes (cupuassu seed, shea nut, murumuru palm waxes), phenolic resins, furane resins, urethanes, epoxy, vinyl chloride, polyethylene and ethyl polyterephthalate.