One of the reaction products between (1) ilmenite and concentrated sulfuric acid is TiOSO4. Adding iron filings can prevent Fe2+ from being oxidized, 2Fe3++Fe=3Fe2+, and ferrous ions are easily oxidized to iron ions. It is only necessary to check whether there are iron ions in the by-products. The experimental method is as follows: a small amount of by-product A is dissolved in water, and an appropriate amount of KSCN solution is added dropwise to observe whether the solution turns blood red.

Therefore, the answer is: prevent Fe2+ oxidation; Take a little by-product A and dissolve it in water, and drop appropriate KSCN solution to observe whether the solution turns blood red. If it turns blood red, it proves that it has deteriorated, otherwise it has not deteriorated.

(2) To obtain the crystal A from the solution I, it is necessary to evaporate and concentrate, cool and crystallize, and filter and wash to obtain the crystal. In addition to beaker and funnel, another glass instrument is used for filtration operation. The main function of glass rod in this operation is to accelerate the dissolution of glass rod by stirring, so that all reactants can fully contact, accelerate the reaction speed and improve the leaching rate of reactants;

So the answer is: evaporation and concentration, cooling and crystallization, filtration and washing; Glass rod, stirring to accelerate dissolution, and make all reactants fully contact, speed up the reaction and improve the leaching rate of reactants;

(3) The reaction of TiO _ 2 to TiCl4 _ 4 is generated by the reaction of TiO _ 2 with carbon and chlorine. The chemical equation of the reaction is: TiO _ 2+2c+2cl2 =? High temperature? . ? TiCl 4+2CO； Titanium dioxide can be obtained by calcination of titanic acid, and metallic titanium can be obtained by electrolysis of molten titanium dioxide, that is, TiO2? Turn it on? . ? Ti+O2↑, advantages: simple process, high atom utilization rate, no pollution to the environment, disadvantages: high energy consumption,

So the answer is: TiO2+2C+Cl2=? High temperature? . ? TiCL4+2CO has the advantages of simple process, high atom utilization rate and no pollution to the environment; Disadvantages: high energy consumption;

(4) The process consumes 33.6LCl2 (standard temperature and pressure), and the amount of substances = 33.6l22.4l/mol = 1.5mol. According to the reaction Fetio3+2h2so4 = Tioso4+FeSO4+2h2o, TiO2+2C+2Cl2=TiCl4+2CO,

Get FeSO4? 7H2O~TiOSO4~TiO2~2Cl2，

1? 2

0.75? Mol 1.5 mol

Crystal mass = 0.75mol×278g/mol = 208.5g；;

So, the answer is: 208.5g；;