Efficient wet-process phosphoric acid graphite heat exchanger scale inhibitor, preparation method and application

Abstract

The invention provides an efficient wet-process phosphoric acid graphite heat exchanger scale inhibitor which comprises, by weight, 28-38 parts of dodecyl polyoxypropylene ether sulfonate, 27-32 partsof succinic acid and 35-50 parts of cosolvents. The scale inhibitor is fed into an inlet and outlet port of a concentrated graphite tube array, the scale inhibitor and diluted phosphoric acid are mixed and then enter the concentrated graphite tube array, scaling of the graphite tube array is stopped and delayed under the action of chelation, solubilizing, lattice distortion and dispersion, original scale of the graphite tube array can be stripped and cleaned, the corrosion rate of an acid side pipeline is reduced, so that the start-up cycle of wet-process phosphoric acid production is prolonged, the heat exchange efficiency of the graphite tube array is improved, energy is saved, consumption is reduced, output is improved, and production cost is reduced.

Description

technical field [0001] The invention relates to the technical field of wet-process phosphoric acid scale inhibition, in particular to a high-efficiency wet-process phosphoric acid graphite heat exchanger scale inhibitor. Background technique [0002] The production process of wet-process phosphoric acid adopts the reaction of ore pulp that meets the process requirements with sulfuric acid, vacuum suction filtration, forced circulation vacuum evaporation and concentration, and finally obtains the product. Due to the indirect heat exchange between the low-pressure steam and the graphite heat exchanger in the process of concentration, the forced circulation of the axial flow pump, and the evaporation and removal of part of the water under vacuum conditions, the P 2 o 5 ≥23.5% of water in dilute phosphoric acid evaporates to give P 2 o 5 ≥46% concentrated phosphoric acid. During the evaporation and concentration process, due to the overflow of water in the form of water vapo...

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Problems solved by technology

In this patent, there will be a large number of bubbles in the scale inhibitor during the concentration process, which will affect the load and make production difficult; secondly, the scale inhibitor is a single formula, which does not only serve the purpose of scale inhibition, but also leads to scale inhibition in order to achieve the purpose of scale removal. The cycle is not long

The patent "loaded scale inhibitor for wet-process phosphoric acid production and its preparation method and use method" (application number: 201810732057.9) is mainly used as a scale inhibitor for pipelines, and it is mainly the crystallization of calcium sulfate, and the viscosity of the added agent will increase , resulting in increased power consumption such as condensed steam

figure 1 Shown is the structural diagram of the wet-process phosphoric acid concentration graphite tube evaporation system in the prior art. During the evaporation and concentration process, due to the overflow of water in the form of water vapor, the fluorosilicate in phosphoric acid is saturated and crystallized, resulting in graphite tube acid Scaling on the side will block the graphite tubes and affect the heat exchange between the steam between the tubes and the phosphoric acid inside the tubes. It will take about 30 days to stop production to clean the graphite tubes. When the operation is started for 20 days per cycle, the operating parameters and indicators will deteriorate significantly, and the production load will gradually decrease. , the cost of acid steam and power consumption per ton of finished product is gradually increasing

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