Directional development method for low-quality coal flotation collecting agent

The invention discloses a directional development method for a low-quality coal flotation collecting agent, and is suitable for collecting agent research. The method comprises the following steps: by taking waste plastics as a raw material, performing directional pyrolysis in a pyrolysis device after pretreatment, purifying and collecting tar in light components generated by pyrolysis, analyzing the composition of the components, and selecting the types of medicaments needing to be continuously compounded for the first time; after surface structure and functional group distribution characteristic analysis of raw coal, subjecting the pyrolytic tar and all agents needing to be compounded to directional screening, and testing the adsorption characteristic of each agent molecule on the coal surface through a single molecule force spectrum testing technology, and optimizing the agent compounding scheme according to the adsorption characteristic effect and then determining the optimal low-rank coal collecting agent