Abstract: The present disclosure provides a method for optimizing a liquid injection process of ionic rare earth ore, including the following steps of: 1) testing the hydraulic properties of an ore body; 2) determining the diffusion degree of the ore body; 3) determining the spatial distribution of the rare earth grade and the impurity grade of the ore body prior to leaching; 4) determining model parameters of competitive exchange of rare earth ions and impurity ions with ammonium ions; 5) obtaining distribution of rare earth ion concentration within the ore body after completion of leaching; 6) obtaining a profile plot of a rare earth leaching rate as a function of the concentration and dosage of an injected leaching agent; and 7) determining a minimum leaching agent dosage to achieve a target leaching rate according to the profile plot, and then determining the ammonium sulfate concentration according to the minimum leaching agent dosage.

Abstract: The present disclosure provides a method for optimizing a liquid injection process of ionic rare earth ore, including the following steps of: 1) testing the hydraulic properties of an ore body; 2) determining the diffusion degree of the ore body; 3) determining the spatial distribution of the rare earth grade and the impurity grade of the ore body prior to leaching; 4) determining model parameters of competitive exchange of rare earth ions and impurity ions with ammonium ions; 5) obtaining distribution of rare earth ion concentration within the ore body after completion of leaching; 6) obtaining a profile plot of a rare earth leaching rate as a function of the concentration and dosage of an injected leaching agent; and 7) determining a minimum leaching agent dosage to achieve a target leaching rate according to the profile plot, and then determining the ammonium sulfate concentration according to the minimum leaching agent dosage.

Abstract: A decorative lighting unit for a string-lights, especially for a LED string-lights, comprises: a LED-lamp and a plurality of connection leads. Said decorative lighting unit further comprises a leg-locating block, a LED-lamp holder and a transparent plate with decorative patterns formed therein. Said LED-lamp, transparent plate and leg-locating block are assembled together. Said LED-lamp comprises a lamp head and lamp legs. Said lamp legs pass through the leg-locating block and are inserted into the LED-lamp holder. Said lamp legs are electrically coupled to the connection leads. Compared with conventional technology, the LED string-lights incorporated with the decorative lighting units of the invention make the patterns formed on the plate glowing and thus bring comfortable effect, since the light radiated from the LED-lamp is directed to the transparent plate.