US 10,494,270 B2  57  58  done in collaboration with the sample collection every hour,  it consists of: pH, density, E:A ratio, chemical volume,  extractant depth, and mixer tip speeds. Once the data has  been collected it will immediately be place inside of the lab  notebook. The samples are then sent off for Inductive  Coupled Plasma (ICP) and Inductive Coupled Plasma Mass  Spectrometry (ICP-MS) analysis.  At the end of this test 3 7 .2 gallons of acid mine drainage  feed had been used over the course of approximately 40  hours.  This example determined the effect of sulfate extraction  efficiency using extractant phase formulation. The apparatus  of FIG.  13  was constructed. The extractant phase was  prepared by selecting components from Table 3, and certain  components of these were selected and blended in propor› tions given in Table 5. The test conditions used are given in  Table 5.  The experiment used extractant solution from Table 5 to  extract sulfate from 2000 ppm Na$_{2}$SO$_{4 }$ solution. Since the  extraction of sulfate anions in a Na$_{2}$ SO$_{4 }$ solution rely mainly  on a concentration gradient, this set-up served as "worst  case" in sulfate anion removal of water purification process.  The extractant solution was treated with 15% Na$_{2}$CO$_{3 }$ to  load up the extractant with carbonate anion, and then the  extractant and Na$_{2}$ SO$_{4 }$ solution were tested under different  E/A ratio. The aqueous phase was analyzed using ion  chromatography to determine the remaining sulfate concen› tration. The ion chromatography results determined the  amount of sulfate removed at different E/A ratio. And those  results were also plotted via McCabe-Thiele plot, which lead  to the discovery of the stages needed for sufficient sulfate  loading and stripping of the water treatment process. The  experiment also determined the range of extractant needed  for effective sulfate extraction, which preferred by the  invention is about 5-15%, most preferably 8-12%. The  McCabe-Thiele result is shown in FIG.  9  to FIG.  12.  To validate the results, a sulfate extraction process was set  up with the apparatus of FIG.  13.  This process was designed  to extract sulfate anion from a 2000 ppm Na$_{2}$ SO$_{4 }$ solution  via a continuous circuit. The result from this process vali› dated the proposed design and the same sulfate process  apparatus was implemented into the overall process flow  scheme. This also established a baseline test condition,  which includes E/A ratio between 1/4-1/6 for sufficient  sulfate extraction and stripping in three to four stages.  This example determined the effect of metal and sulfate  extraction efficiency in a less contaminated stream using  extractant phase formulation. The apparatus of FIG.  14  was  constructed. The extractant phase was prepared by selecting  components from Table 3 blended in proportions giving in  Table 5. The test conditions used are given in Table 5.  This experiment used extractant solution from Table 5  with process apparatus of FIG.  14  to perform water purifi› cation process with an acid mine drainage stream containing  low contaminant levels. The process was set up with the  same number of extracting and stripping stages. The com› bination of high extraction efficiency of metal cation and  sulfate anion and the low contaminant concentration in the  acid mine drainage stream caused secondary emulsion at the  third extraction stage. The emulsion also stopped phase  disengagement between extractant solution and the raffinate.  The extractant solution and raffinate emulsion created from  the process behaved similarly to an emulsion of an extract› ant solution and deionized water. The emulsified raffinate  from this process was left in the tank for 24 hours to prolong  the settling time in an attempt to achieve better phase  disengagement. However, there was no visible phase sepa› ration after 24+ hours of settling time, and the emulsion was  not able to break until pH adjustment was made by addition  of sulfuric acid. It appears that mixing was excessive thus  forming a stable microemulsion. Stable in that the disen› gagement from the emulsion was too slow. When mixer  speed was controlled this problem did not return.  This example determined the effect of acid mine drainage  liquid-liquid extraction (LLX) system efficiency with  shorter mixing residence time using extractant phase for› mulation. The apparatus of FIG.  14  was constructed. The  extractant phase was prepared by selecting components from  Table 3 blended in ranges given in Table 4. The test  conditions used are given in Table 5.  This experiment also used extractant solution from Table  5 with process apparatus of FIG.  14  to evaluate acid mine  drainage water purification process performance under  shorter mixing residence time. The two-part experiment  tested different process conditions; the first part of the  experiment tested the treatment process with E/Aratio of 1/6  and mixing residence time of 60 seconds, and the second  part tested the treatment process with E/ A ratio of 1/8 and  mixing residence time of 35 seconds.  The 60 seconds mixing residence time trial was behaving  well on its own, and the consumption rates of Na$_{2}$CO$_{3 }$ and  H$_{2}$SO4 were determined in this experiment. The raffinate  from individual stream was sent to ion chromatography and  Inductively Coupled Plasma Mass Spectrometry (ICP/MS)  to determine the final metal and sulfate concentration. These  results and measurements helped to determine the final  mass/molar balance of the overall process. The 35 seconds  mixing residence time trial also had a smooth operation.  However, the raffinate’s ion chromatography and ICP/MS  results from this trial turned out not fulfilling the perfor› mance requirement. This allowed the determination of the  mixing residence time and E/ A ratio limitation for the  treatment system. The analytical results from these trials are  shown in Table 6.  The result from the two-part experiment not only showed  the limitation of E/ A ratio and mixing residence time needed  for sufficient process treatment, but also determined the  extractant solution input rate with respect to the mixer size.  If too much extractant solution pushed into strippers, the  mixer section would be overwhelmed and started plugging  up because of the excess extractant solution in the mixer.  The excess extractant solution in the mixer had gel-like  behavior and caused the mixer to lose hydraulic suction.  This would severely cripple the process because it was  essentially equal to shutting down the process at midpoint  while more acid mine drainage water and extractant were  being pushed through the front end of the process. The  discovery of this particular limitation allowed the determi- nation of the maximum extractant solution flow rate into the  strippers, thus provided the boundary condition needed for  the process.  This example determined the effect of water entrainment  from extractant phase formulation, especially the contribu- Example 4  Example 2 (Run #2)  Example 3 (Run #6)  Example IA (Stages Determination) 